Chapter 1 Integers Idea and Examples Chart
Transcript of Chapter 1 Integers Idea and Examples Chart
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Chapter 1 Integers
Idea and Examples Chart
1–6. Sample answers are given.
1. Integers: … , −3, −2, −1, 0, 1, 2, 3, …
Example
−586
Example
0
Example
16
2a. Adding integers with the same sign:Add the absolute values of the integers.Then use the common sign.
Example
16 + 17 = 33
−5 + (−4) = −9
−55 + (−45) = −100
Example
Example
2b. Adding integers with different signs:Subtract the lesser absolute value from thegreater absolute value. Then use the sign ofthe integer with the greater absolute value.
Example
−8 + 2 = −6
−97 + 19 = −78
8 + (−2) = 6
Example
Example
3. Additive Inverse Property: The sum of an integer and its additive inverse, or opposite, is 0.
5 + (−5) = 0
Example
−100 + 100 = 0
Example
16 + (−16) = 0
Example
4. Subtracting integers: To subtract an integer,add its opposite.
1 − 4 = 1 + (−4) = −3
Example
−1 − (−4) = −1 + 4 = 3
Example
1 − (−4) = 1 + 4 = 5
Example
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Chapter 1 (continued)
5a.
Example
−6 · (−3) = 18
6 · 3 = 18
−18(−16) = 288
Example
Example
Multiplying integers with the same sign: The productof two integers with the same sign is positive.
5b.
Example
−6 · 3 = −18
6 · (−3) = −18
18(−16) = −288
Example
Example
Multiplying integers with different signs: The productof two integers with different signs is negative.
6a. Dividing integers with the same sign: Thequotient of two integers with the same signis positive.
100 ÷ 4 = 25
Example
−100 ÷ (−4) = 25
Example
−98−7
Example
= 14
6b. Dividing integers with different signs: Thequotient of two integers with different signsis negative.
100 ÷ (−4) = −25
Example
−100 ÷ 4 = −25
Example
−987
Example
= −14
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Chapter 2 Rational Numbers
Process Diagram
1–4. Sample answers are given.
1.
ab
Use long division to findthe quotient a ÷ b.
Write the rational numberas a fraction if necessary.
Writing rational numbersas decimals
as a decimal.Write −5 15
= −5.2.So, −5 15
Example
If the remainder is 0,the rational number is a
terminating decimal.
=−5 15
− 265
26.05.2
52 5
1 0−
1 00
−
as a decimal.Write 215
215
= 0.13.So,
Example
If the remainder repeats,the rational number is a
repeating decimal.
2.0000. 1 33
151 5
5045
−
−5045
5−
2. Subtracting rational numbers
=− 14
−− 32
− 14
+ 32
= − 14
+ 64
= 54
, or 1 14
Add the opposite of the rationalnumber being subtracted.
if the addends havedifferent signs
Subtract the lesser absolute valuefrom the greater absolute value.
Write the sum using the sign ofthe rational number with the
greater absolute value.
9.03 − 5.41 = 9.03 + (−5.41)= 3.62
Examples
=−2 58
−2 58
1 38
−1 38
− +
= −4
2.58 − (−3.67) = 2.58 + 3.67= 6.25
Examples
if the addends havethe same sign
Add the absolute valuesof the rational numbers.
Write the sum usingthe common sign.
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Chapter 2 (continued)
3. Multiplying rationalnumbers
If the factorshave the same sign
If the factorshave different signs
The product is positive. The product is negative.
(––) (––) = (––) (––)Examples Examples
= —
34
29
34
29
= – 16
–3.7× –2.4
1 48+ 7 4
8.88
1
2
1
3
The product is 8.88.
12
(–2–) (––)= —
35
13
35
73
= ––, or –1– 75
25
–2.64 5
14
–1.1
1
1
The product is –1.17.
23
4.
(− )
Dividing rationalnumbers
If the dividendand divisor havethe same sign
If the dividendand divisor havedifferent signs
The quotient is positive. The quotient is negative.
–2.45 ÷ (–0.7) = 3.5
Examples Examples
–6 ÷ (– ) = – ÷ (– )14
14
15
254
1551
= – 254
= –
= 1254 , or 31
–2.45 ÷ (0.7) = –3.515
310
23
15
32
= –
= –
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Chapter 3 Expressions and Equations
Four Square
1–7. Sample answers are given.
1.
5x2 + 6x – 3x2 + 8 – x= 5x2 + 6x + (–3x2) + 8 + (–1x)= 5x2 + (–3x2) + 6x + (–1x) + 8= [5 + (–3)]x2 + [6 + (–1)]x + 8= 2x2 + 5x + 8
Definition
An algebraic expressionis in simplest formwhen it has: 1. no like terms and 2. no parentheses.
WordsTo write an algebraicexpression in simplestform:Step 1: Rewrite as a sum.Step 2: Use theDistributive Property onparentheses, if necessary.Step 3: Rearrange terms.Step 4: Combine like terms.
Simplest form
Example9 – 3(–m ––) + 3m
= 9 + (–3)(–m + (––)) + 3m
= 9 + (–3)(–m) + (–3)(––) + 3m
= 9 + (–2m) + 1 + 3m= (–2m) + 3m + 9 + 1= (–2 + 3)m + (9 + 1)= m + 10
Example13
23
23
13
13
23
2.
(7 – w) + 3(–2w + 4)= 7 + (–1w) + 3(–2w) + 3(4)= 7 + (–1w) + (–6w) + 12= (–1w) + (–6w) + 7 + 12= –7w + 19
Definition
An algebraic expressionin which the exponentof the variable is 1
Examples
–7x, 2x + 3, 8 – –x
Non-examples:
x3, –5x2 + x, x7 – 9
Linear expressionExampleAdding linear expressions:
(4y + 7) – (y – 8) 4y + 7–(1y – 8)
4y + 7(–1y) + 8 3y + 15
Subtracting linearexpressions:
Example
14
+
3.
–r = – r
– = –
–r + – = – r + –
= –(r
Words
Write the expression asa product of factors.You can use theDistributive Property.
Example
Factor 12athe GCF.12a a
612a 6(2a 6 = 6(2a
ExampleFactor – out of –r + –.
–21p = –7 p 28 = –7–21p + 28 = –7 p = –7 p
Factor –7 out of –21p + 28.
Example
1
1
1 1 1
1
1
1 1
4. WordsTwo equations areequivalent equations ifthey have the samesolutions. You can usethe Addition, Subtraction,Multiplication, andDivision Properties ofEquality to write equivalentequations.
Algebra
a = b and a + c = b + ca = b and a – c = b – ca = b and a c = b c
a = b and – = –, c ≠ 0
Equivalent equationsExamplesx – 7 = 2 andx – 7 + 7 = 2 + 72d + 5 = –7 and2d + 5 – 5 = –7 – 524 = – and–4 24 = –4 –3c = –12 and – = –
x + 7 = 2 andx + 7 – 7 = 2 + 73c = –4 and – = (–4)7 = m + 3 and7 – 7 = m + 3 – 33x + 7 = 3 and 3x = 7 + 3
Non-Examples
y–4 y
–43c3
3c3
–123
ac
bc
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Chapter 3 (continued)
5. WordsTo undo addition, use theSubtraction Property of Equality:subtracting the same numberfrom each side of an equationproduces an equivalent equation.To undo subtraction, use theAddition Property of Equality:adding the same number to eachside of an equation produces anequivalent equation.
Algebra
If a + b = c,then a + b – b = c – b.
If a – b = c,then a – b + b = c + b.
Solving equations usingaddition or subtraction
Example
x – 4 = 12 +4 +4 x = 16
Check x – 4 = 1216 – 4 = 12 12 = 12
Example
?x + 4.1 = 12 –4.1 –4.1 x = 7.9
Check x + 4.1 = 127.9 + 4.1 = 12 12 = 12
?
6. WordsTo undo multiplication, use theDivision Property of Equality:dividing each side of an equationby the same number producesan equivalent equation.To undo division, use theMultiplication Property ofEquality: multiplying each side ofan equation by the same numberproduces an equivalentequation.
Algebra
If ab = c,then – = –, b ≠ 0.
If – = c,then – = b c, b ≠ 0.
Solving equations usingmultiplication or division
Example
–2x = 3–2x = 3 –2 –2 x = ––, or –1–
Check –2x = 3–2(––) = 3 3 = 3
Example
?
abb
cb
ab a
b
32
12
32
– = –3
– = (–3) x = –6
Check – = –3
– = –3
–3 = –3
?
x2x2
x2
–62
7. WordsUndo the operations in thereverse order of the orderof operations: 1. Undo addition or subtraction. 2. Undo multiplication or division.After solving for the variable,check your solution.
3x + 4 = 1 –4 –4 3x = –3 3x = –3 3 3 x = –1
Solving two-stepequations
Example
Example
– – – = ––
–– ––
–– = –1
– (––) = – (–1) a = 3
Example37
Check – – – = ––
– – – = ––
– + (–1) = ––
– + (––) = ––
–– = ––
?
?
?
37
a3
47
37
33
47
37
47
37
77
47
47
47
37
37
a3
a3
a3
47
Check 3x + 4 = 13(–1) + 4 = 1 –3 + 4 = 1 1 = 1
?
?
4(x – 2) = 124x + (–8) = 12 +8 +8 4x = 20 4 4 x = 5
Check4(x – 2) = 124(5 – 2) = 12 4(3) = 12 12 = 12
?
?
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Chapter 4 Inequalities
Y Chart
1–8. Sample answers are given.
1.
The sign between two expressions is an equal sign, =.
One number is the solution.
Writing equations Writing inequalities
The sign between two expressions is an
inequality symbol: <, >, < or > . More than one number
can be a solution.
Write one expression on the left and one expression on the right. Look for key phrases to determine which operation(s)
to use: +, −, ×, or ÷. Look for key phrases to determine where to place the
equal or inequality sign.
2.
A solution is represented by a closed circle, .
One number is the solution.
Graphing the solution of an equation
Graphing the solution of an inequality
The endpoint of the graph can be an open circle, ,
or a closed circle, . An arrow pointing to
the left or the right shows that the graph continues
in that direction. More than one number can
be a solution.
Solve for the variable. Graph the solution on a number line.
3.
For x greater than a number, use an arrow pointing to the right.
Graphing inequalities that use >
Graphing inequalities that use <
For x less than a number, use an arrow pointing to the left.
Use a number line to graph the solution. Use an open circle, . Use an arrow to show that the graph continues. Solution usually includes many numbers.
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Chapter 4 (continued)
4. Graphing inequalitiesthat use > or <
Graphing inequalitiesthat use ≥ or ≤
Use an open circle, .
Use a number line.Use an arrow to show that the graph continues.
Use a closed circle, .
5. Solving inequalitiesusing addition
Solving inequalitiesusing subtraction
Use the Addition Property of Inequality: When you add the same number to each side of an inequality, the inequality remains true.
Use inverse operations to group numbers on one side.
Use inverse operations to group variables on one side.
Solve for the variable.
Example: x – 5 > 8 +5 +5 x > 13
Use the Subtraction Property of Inequality: When you subtract the same number from each side of an inequality, the inequality remains true. Example: x + 5 > 8 –5 –5 x > 3
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Chapter 4 (continued)
6.
Use the Multiplication Property of Inequality(Case 1): When you multiplyeach side of an inequality bythe same positive number, the inequality remains true.
Use the Multiplication Property of Inequality(Case 2): When you multiplyeach side of an inequality bythe same negative number, the direction of the inequality symbol must be reversed for the inequality to remain true.
Use the Division Property of Inequality (Case 1): When
you divide each side of an inequality by the same
positive number, the inequality remains true.
Use the Division Property of Inequality (Case 2): When
you divide each side of an inequality by the same
negative number, the direction of the
inequality symbol must be reversed for the
inequality to remain true.
Solving inequalities using multiplication
Solving inequalities using division
Use inverse operations to group numbers on one side. Use inverse operations to group variables on one side. Solve for the variable.
Example: – > 10
– 5 > 10 5 x > 50
x5
x5
Example: ––x ≤ 10
–– (––x) ≥ –– 10 x ≥ –20
12
21
12
21
Example: 5x > 10
–– > –– x > 2
5x5
105
Example: –3x ≥ 9
–– ≤ –– x ≤ –3
–3x–3
9–3
7. Solving two-step equations
Solving two-stepinequalities
Use inverse operations to isolate the variable. Group numbers on one side, variables on the other side,
and solve for the variable.
The sign between two expressions is an equal sign, =.
One number is the solution.
The sign between two expressions is an
inequality symbol: <, >, < or > . More than one number
can be a solution.
8. Adding integerswith the same sign
Adding integerswith different signs
Sums can be negative or positive.
Add the absolute values of the integers. Then use the common sign.
Subtract the lesser absolute value from the
greater absolute value. Then use the sign of
the integer with the greater absolute
value.
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Chapter 5 Ratios and Proportions
Information Wheel
1–8. Sample answers are given.
1.
Rate
A ratio of two quantities
with different unitsExample:
Unit rate: A rate with
a denominator of 1
63 feet12 seconds
Example: 8 hits25 at bats
Example:$135
3 hours
Example of a unit rate:60 miles1 hour
2.
Unitrate
A rate with a denominator of 1Example: 5.25 feet
1 second
Example:You can write rates as unit rates.
=400 units
8 hours
50 units
1 hourExample:
You can write unit rates as
rates with denominators other than 1.=
0.5 mile1 hour 1 mile2 hours
Example: 60 miles1 hour
Example:72 words
1 minute
3.
Proportion
An equation stating that
two ratios are equivalentExample: =
You can use a table to write a
proportion. Example: See page 180.
The cross products of a proportion are equal. Example: 3 · 8 = 4 · 6
To solve a proportion,
you can use mental math.
Two quantities that form a proportion
are proportional.
34
68
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Chapter 5 (continued)
4. The products a · d and b · c
in the proportion = Cross Products Propert
y
In words: The cross products
of a proportio
n are equal.
You can use t
he Cross Products
Property t
o solve a proportio
n. Example: =
2 · x = 3 · 4
x = 6
Numbers: = The cross productsare 3 · 8 and 4 · 6. Note that they
are both equal to 24.Cross products
Cross Products Property usingalgebra: ad = bc in = ,
where b ≠ 0 and d ≠ 0
ab c
d
34
68 a
bcd
23 4
x
5. The graph has a constant rate
of change.
The graph passes th
rough the o
rigin.
Example: Find the unit r
ate.
– = –32
1.51
The graph is a line that passes
through the origin. So, x and y are in
a proportional relationship.
Example:
Graphingproportionalrelationships
Example:
xy
23
46
69
+2
+3 +3
+2
0
2
4
6
8
y
0 2 4 6 8 x
6. Method 1: Use mental math.
Example: =
5 · 2 = 10
, so x = 1 ·
2 = 2
Method 3: U
se the C
ross
Products Propert
y.
Example: =
1 · 10 = 5 · x
10 = 5x
2 = x
Method 2: Use the MultiplicationProperty of Equality. Solving
proportions
Example: = 10 · = 10 ·1
515
x10
x10
15 x
10
15
x10
2 = x
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Chapter 5 (continued)
7. Rate of change between
any two points on a line
A measure of the
steepness of a line
Through (0, 0) and (4
, 3):
slope =
Through (2, 3) and (−6, −3):
slope = =
vertical changehorizontal change Slope
change in ychange in x
34
34
−6−8
8. Two quantities x and y show
direct variation when y = kx,
where k is a number and k ≠ 0. The graph of y
= kx is a lin
e that
passes through th
e origin.
y = 4x
k = 4
y = xk =
“y varies directly with x.” Directvariation
“x and y are directly proportional.”
14
14
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Chapter 6 Percents
Summary Triangle
1–8. Sample answers are given.
1.
Writing a decimal
as apercent
Multiply by 100, or just move the decimal point two
places to the right. Then add a percent symbol.
n = (n 100)%
Example: 0.231 = 23.1%
2.
Write the numbersas all fractions, all decimals,
or all percents. Then compare.Use a number line if necessary.
Comparingand ordering
fractions,decimals, and percents
Examples:Which is greater, 5.1% or ? = = 5%. So, 5.1% is greater.
Which is greater, 3.3% or 0.03?3.3% = 0.033. So, 3.3% is greater.
1201
205
100
3.
Example: What percent of 40 is 25?
So, 62.5% of 40 is 25.
Use a proportionto represent “a is p
percent of w.”
aw
Thepercent
proportion
p100
2540
p100
=
part
whole
percent
– –62.5 = p
4.
Example: What number is 35% of 60?
So, 21 is 35% of 60.
Use an equationto represent “a is p
percent of w.”
a = p w
Thepercent
equation
35100
percent in fractionor decimal form
part of the whole
whole
a = –
= 21
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Chapter 6 (continued)
5.
Example: Find the percent of change from 15inches to 24 inches. Because 24 > 15, thepercent of change is a percent of increase.
The percent thata quantity changes
from the original amount
percent of change =
Percentof
change
24 – 1515
915
amount of changeoriginal amount
percent of increase = — = – = 0.6, or 60%
6.
Discount
A decrease inthe original price
of an item
Example: An item that originally sellsfor $25 is on sale for 20% off.
What is the sale price?a = 0.2 · 25 = 5 Sale price = 25 − 5 = 20
The sale price is $20.
Discount: a = p · w
= original price − discountSale price
7.
Markup
To make aprofit, stores
charge more thanwhat they pay. The
increase from what thestore pays to the sellingprice is called a markup.
Example: The wholesale price of an itemis $15. The percent of markup is 12%.
What is the selling price?a = 0.12 · 15 = 1.8 Selling price = 15 + 1.8 = 16.8
The selling price is $16.80.
Markup: a = p · wSelling price = cost to store + markup
8.
Money paid orearned only onthe principal
Simpleinterest
Simpleinterest
Example: You deposit $1000 in an accountthat earns 3% simple interest per year.
How much interest will you earn after 4 years?I = Prt = 1000(0.03)(4) = $120
Annual interest rate(in decimal form)
Principal Time (in years)
I = Prt
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Chapter 7 Constructions and Scale Drawings
Example and Non-Example Chart
1–5. Sample answers are given.
1. Adjacent angles
Examples Non-Examples
1 23
1 and 22 and 3
41 2
34
1 and 32 and 4
3 and 44 and 1
ADB and BDCBDC and CDACDA and ADB
AB
C
D
2. Vertical angles
Examples Non-Examples
1 234
1
6 789
5
234
1 and 22 and 33 and 44 and 1
1 and 32 and 4
5 and 8only
AGB and DGEAGF and DGCBGC and EGF
A BC
DEF
G
3. Supplementary angles
Examples Non-Examples
1 2
3 456
3 456
3 and 54 and 6
3 and 44 and 55 and 66 and 3
1 and 2
50˚ 130˚
117˚, 63˚ 104˚, 62˚
4. Quadrilaterals
Examples Non-Examples
5. Scale factor
Examples Non-Examples
5 : 11 : 2001 : 13 : 2
1 cm : 2 mm1 mm : 20 cm12 in. : 1 ft3 mi : 2 in.
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Chapter 8 Circles and Area
Word Magnet
1–5. Sample answers are given.
1. Semicircle
One half of a circle
C = one-half the circumference of a circle with a diameter of d
= –– d2
Perimeter = one-half circumference + diameter = –– + d d
2diameter = 2r
2. Compositefigure
Perimeter = 3 + 3 + 5 + 7 = 18 feet
Example: Example: semicircle
Perimeter = –––– + 3 + 6 + 3 = 12 + 3 21.42 feet
(6)2
Made up of triangles, squares, rectangles, semicircles, and
other two-dimensional figures
7 ft
3 ft
5 ft 6 ft3 ft
3 ft
Perimeter: sum of the lengths around the figure
3. Perimeter
Perimeter = 5(5) = 25 centimeters
Example: Example:
Perimeter = (5) + 5 + 5 = 10 + 5 25.7 feet
Distance around a figure
Sum of the lengths around figure
Measured in linear units, such as feet
The perimeter of a circle is called its circumference.
5 cm
5 cm5 cm
5 cm5 cm
semicircles
5 ft
5 ft
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Chapter 8 (continued)
4. Area of acircle
Example:
times the radius squared A = r²
Diameter = 2 radius d = 2r A = – ²= ––– d²
4d2
A = (14)² = 196 616 square meters
14 m
Example:
(2)²4A = ––––– =
3.14 square meters
2 m
5. Area of acomposite figure
Example: Example:
A = ––––– + 5² = –––– + 25 44.625 square feet
(5)²4
25 4
Made up of triangles, squares, rectangles, semicircles, and
other two-dimensional figures
7 ft
3 ft
5 ft3 ft
To find area, split up into figures with areas you know how to find.
Then add the areas of those figures.
A = 3² + – (3)(4) = 15 square feet
12
semicircles
5 ft
5 ft
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Chapter 9 Surface Area and Volume
Information Frame
1–5. Sample answers are given.
1.
Surface areasof prisms
Visual
ExampleRectangular prism:
Example
S = 2 w + 2 h + 2wh = 2(4)(2) + 2(4)(3) + 2(2)(3) = 16 + 24 + 12 = 52 square inches
S = 2( ·3·4) + 3·6 + 5·6 + 4·6 = 12 + 18 + 30 + 24 = 84 square feet
3 in.
4 ft
4 ft4 ft
5 ft
5 ft5 ft
6 ft
6 ft
3 ft
3 ft
4 in. 2 in.
4 ft
5 ft
6 ft3 ft
12
Words
The surface areaS of a prism is thesum of the areasof the bases andlateral faces.
Triangularprism:
lateralface
lateralface
lateralface
base
base
Triangularprism:
2.
Surface areasof pyramids
Visual
Algebra
S = +
12
Words
The surface areaS of a pyramid isthe sum of theareas of the baseand lateral faces,which aretriangles.
Example
S = 6² + 4 – 6 9 = 36 + 4 27 = 36 + 108 = 144 square inches
12
6 in.6 in.
9 in.
Slantheight
Slantheight
Lateralfaces
Lateralfaces
Base
area of a lateralface (triangle):
A = –bh
area ofbase
areas oflateralfaces
edge ofbase
slantheight
3.
Surface areasof cylinders
Example
5 cm
4 cm
Visual
S = 2πr² + 2πrh = 2π(4)² + 2π(4)(5) = 32π + 40π = 72π ≈ 226.08 square centimeters
WordsAlgebraThe surface
area S of acylinder is thesum of the areasof the bases andthe lateralsurface.
S = 2πr² + 2πrh
Areaof bases Area of
lateralsurface
Base
Base
2πr
h h
r r
r
Lateral surface
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Chapter 9 (continued)
4.
Volumes ofprisms
Example
5 in.
4 in.3 in.
Visual
V = Bh
= 60 cubic inches
Words
AlgebraThe volume Vof a rectangularprism is theproduct of the areaof the base and theheight of theprism.
V = BhArea
of base Heightof prism
area of base, B
height, h area ofbase, B
height, h
5.
Volumes ofpyramids
Example
9 m
5 m4 m
Visual
Words
AlgebraThe volume Vof a pyramid isone-third theproduct of the areaof the base and theheight of thepyramid.
V = –Bh
Areaof base
Heightof pyramid
area of base, B
height, hheight, h
13
V = –Bh131313
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Chapter 10 Probability and Statistics
Notetaking Organizer
1– 7. Sample answers are given.
1.
How can I find the probability of an event without doing an experiment?
Experimental Probability
Probability that is based on repeated trials of anexperiment
P(event) = ––––––––––––number of timesthe event occurs
total number of trials
Example: You flip a coin 100 times. You flip heads 52 times and tails 48 times. The experimental probabilites are
P(heads) = ––– = 0.52 = 52%,
and
P(tails) = ––– = 0.48 = 48%.
52100
48100
Experiment: aninvestigation or a procedure that has varying results
Outcomes: the possible results of an experiment
Event: a collection of one or more outcomes
2.
What if the possible outcomes are not equally likely?
Outcomes: the possible results of an experiment
Event: a collection of one or more outcomes
Favorable outcomes: the outcomes of a specific event
Theoretical Probability
The ratio of the number of favorable outcomes to the number of possible outcomes, when all possible outcomes are equally likely
P(event) = ––––––––––––––number of
favorable outcomesnumber of
possible outcomes
Example: You flip a coin. The theoretical probability of flipping heads and the theoretical probability of flipping tails isP(heads) = –, and
P(tails) = – .
12
12
3.
How do I use the Fundamental Counting Principle to find the probability of more than two events?
Outcomes: the possible results of an experiment
Event: a collection of one or more outcomes
Sample space: the set of all possible outcomes of one or more events
Fundamental Counting Principle
A way to find the total numberof possible outcomes of an event;can use a table or a tree diagram.
Example:The total number of possibleoutcomes of rolling a numbercube and flipping a coin is6 × 2 = 12.
numbercube
coin total
eventM
eventN
M followedby N
An event M has m possibleoutcomes. An event N has npossible outcomes. The totalnumber of outcomes of eventM followed by event N is m × n.
m × n = total
Copyright © Big Ideas Learning, LLC. All rights reserved. Big Ideas Math Red 21
Chapter 10 (continued)
4.
What if the occurence of one event does affect the likelihood of the other?
P(A and B and C) = P(A P(B P(C)
A compound event consists of two or more events.
Choosing with replacement means the events are indepenent.
Independent Events
Events are independentevents if the occurence ofone event does not affect the likelihood that the other event(s) will occur.
P(A and B) = P(A) P(B)
The probability of two or moreindependent events is the product of the probabilitiesof the events.
P(1 and 1) = P(1) P(1)
=
=
probabilityof bothevents
probabilityof firstevent
probabilityof second
event
13
13
19
Example: A spinner hasthree equal sectionsnumbered 1, 2, and 3. Youspin it twice. What is the probability of spinning a 1 both times?
5.
How do you use probability to make predictions?
A compound event consists of two or more events.
Choosing without replacement means the events are dependent.
Events are dependentevents if the occurence ofone event does affect the likelihood that the other event(s) will occur.
P(A and B) = P(A) P(B after A)
The probability of twodependent events A and B is the probability of A times the probability of Bafter A occurs.
probabilityof bothevents
probabilityof firstevent
probabilityof second
event afterfirst event
occurs
Dependent Events
P(red and red)
= P(red) P(red after red)
=
= 29
49
510
Example: You have 5 red cardsand 5 blue cards. You randomlychoose one card. Withoutreplacing the first card, yourandomly choose a secondcard. What is the probabilitythat both cards are red?
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Chapter 10 (continued)
6.
How do you select an unbiased sample from a largepopulation?
Sample
Part of a population
The results of an unbiased sample are proportional to the results of the population. So, you can use unbiased samples to make predictions about the population.
Biased samples are not representative of the population. So, you should not use them to make predictions about the population because the predictions may not be valid.
Example:Population: All of the seventh-grade students in your schoolUnbiased sample: 100 seventh-grade students selected randomly during lunchBiased sample: The seventh-grade students at your lunch table
An unbiased sample is representative of a population. It is selected at random and is large enough to provide accurate data.
A biased sample is not represen-tative of a population. One or more parts of the population are favored over others.
Population
Sample
Interpretation
Inference
7.
How can you tell whether a distribution is skewed or symmetric?
Population
An entire group of people or objects
To compare two populations, use the mean and the MAD when both distributions are symmetric. Use the median and the IQR when either one or both distributions are skewed.
You do not need to have all the data from two populations to make comparisons. You can use random samples to make comparisons.
An inference about a population is more precise if you use multiple samples.
Mean: the sum of the data divided by the number of data values
Median: For a data set with an odd number of ordered values, the median is the middle value. For a data set with an even number of ordered values, the median is the mean of the two middle values.
Interquartile range (IQR): the difference between the third quartile and the first quartile
Mean Absolute Deviation (MAD): an average of how much data values differ from the mean