Trendlines & Excel. Same Log In Press: Control-Alt-Delete Username: physics Password: success.
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Transcript of Trendlines & Excel. Same Log In Press: Control-Alt-Delete Username: physics Password: success.
Use Your Old Data
food (pellets/day) mass (g)
1 6
2 8
3 13
4 15
5 25
6 34
7 52
8 78
9 94
10 121
After 6 months…
Do Over: Enter Your Data
• Row 1: Names
• Row 2: Date
• Row 3: Blank
• Row 4: Headings
• Row… : Data
Graph It Again
Goldfish Growth
0
20
40
60
80
100
120
140
0 2 4 6 8 10 12
Food (pellets/day)
Mas
s (g
)
Ingredients:
• Meaningful Title
• Labeled Axis
• Units in Parentheses
• White Background
• No Gridlines
Mathematical Relationships(Trend Lines)
Have Excel draw lines through your data.
Pick the “best fit” line.
Excel gives you the equation.
Use the equation to make a prediction.
Ex: Calculate the goldfish’s mass if it is fed 7.5 food pellets per day.
Example: Add a “Best Fit” Trend Line to our Goldfish Growth Graph
Goldfish Graph
Next: You add a best fit trend line
to the examples.
Linear Relationship
• Use a straight line.
• Mathematically:
• The dependent variable (y) does the same thing as your independent variable (x).
bmxy
Inverse Relationship
• Excel calls this a Power function
• Mathematically:
• exponent = -1 ← makes this an inverse
• Your dependent variable (y) does the opposite of your independent variable (x)
1axx
ay
Quadratic Relationship
• Excel calls this a Polynomial function• Order = 2 ← this makes it a quadratic
• Mathematically: cbxaxy 2
Your Turn
Find the best fit trend line. Use the equation to predict how far it would take your cart to stop if released from 65 cm.