STAT 200 FINAL EXAMINATION, SPRING 2017 STAT 200 FINAL EXAMINATION, | Page 6

confidence interval estimate of the mean daily income this parking garage generates. ​ Show all
work. Just the answer, without supporting work, will receive no credit
15. ​ A researcher claims the proportion of auto accidents that involve teenage drivers is less
than 20%. ABC Insurance Company checks police records on 200 randomly selected auto
accidents and notes that teenagers were at the wheel in 32 of them.
Assume the company wants to use a 0.05 significance level to test the researcher’s claim.
1. (a) Identify the null hypothesis and the alternative hypothesis.
2. (b) Determine the test statistic. ​
Show all work; writing the correct test statistic,
without supporting work, will receive no credit.
3. (c) Determine the ​
P ​ -value for this test. ​ Show all work; writing the correct P-value,
without supporting work, will receive no credit.
4. (d) Is there sufficient evidence to support the researcher’s claim that the proportion
of auto accidents that involve teenage drivers is less than 20%? Explain
16. ​ Mimi was curious if regular excise really helps weight loss, hence she decided to perform a
hypothesis test. A random sample of 5 UMUC students was chosen. The students took a
30-minute exercise every day for 6 months. The weight was recorded for each individual before
and after the exercise regimen. Does the data below suggest that the regular exercise helps
weight loss? Assume Mimi wants to use a 0.05 significance level to test the claim
1. (a) Identify the null hypothesis and the alternative hypothesis.
2. (b) Determine the test statistic. ​
Show all work; writing the correct test statistic,
without supporting work, will receive no credit.
3. (c) Determine the p-value. ​
Show all work; writing the correct critical value, without
supporting work, will receive no credit.