Homework Questions?. Section 9.3 Tests about a Population Mean.
-
Upload
beatrice-beasley -
Category
Documents
-
view
223 -
download
0
Transcript of Homework Questions?. Section 9.3 Tests about a Population Mean.
Homework Questions?
Section 9.3
Tests about a Population Mean
One Sample t Test
Find the p-value by calculating the probability of getting a t statistic this large or larger in the direction specified by the alternative hypothesis with
Computing the test statistic and p-value of AAA batteries from section 9.1 The battery company wants to test vs. based
on a SRS of 15 new AAA batteries with a mean lifetime of hours and standard deviation hours. What is the test statistic? (t)
Find the p-value.
Can we still make conclusions?
Two-Sided Tests What if you were performing a test of vs.
based on a sample of and obtained ?
Example – Health Streams The level of dissolved oxygen (DO) in a stream
or river is an important indicator of the water’s ability to support aquatic life. A researcher measures the DO level at 15 randomly chosen locations along a stream. Here are the results in mg/l:
A DO level below 5 mg/l puts aquatic life at risk.
4.53
5.04
3.29
5.23
4.13
5.50
4.83
4.40
5.42
6.38
4.01
4.66
2.87
5.73
5.55
XX
Healthy Streams Can we conclude that aquatic life in this
stream is at risk? Carry out a test at the significance level to help you answer the question.
State:
Plan:
Healthy Streams Do:
Conclude:
Healthy Streams Given your conclusion, which kind of mistake –
Type I or Type II error – could you have made? Explain what this would mean in context.
Again…look at a confidence interval… Look at 95% confidence interval… For means:
Paired Data - Flip to page 581 Matched Pairs! Only do (3, 4, 5)
Homework
Pg. 587 (63-69 odd, 70, 73-79 odd, 91, 95, 96, 99-104)