Warm-upDay before Cumulative Test

State the conditions you must check for each of these inference testsor confidence interval.

Answers to multiple choice1) B 2) A 3) E 4) D 5) C 6) C 7) D 8)C

9) C 10) B 11) B 12) E

Complete Free-Response• It should take you no more than 45 minutes to complete

the free-response.• Work on it quietly. When I see the 45 minutes are up or

most of you are finished we will review the answers.• If you finish early, read the project description.

Write 2 questions about the project not detailed on the description.

• I will check to see if you wrote these questions down next block for homework.

• Next block:we will discuss your project questions.• I will explain the project in more detail.• You will have about 30 to 40 minutes to complete the

multiple choice portion of your cumulative test.

Answers to A.P. Statistics Practice Test

FREE RESPONSE1) a.

b. I would recommend A because 75% of the values are higher than the values those in additive B.

c. If my goal was to choose the additive wit the highest average, I would choose additive B because the higher values bring up the mean above the median. This will make B have the higher mean.

Free Response Answers2.a. We are told the sample of pavers is a random sampleand it is reasonable to believe that more than 510 of themare manufactured.The success/failure condition is met 51 (0.8) = 40.8 > 10 and 51(0.2) =10.2 > 10The conditions are met to perform a one proportion z-test.The conditions are Ho: p = 0.80

HA: p ≠ 0.80

61036.183.4056.0

8.0529.0

056.051

)2.0(8.0..529.0

51

27ˆ

valuepzstatistictest

ESp

Free Response Answers Continued…

The hypothesized amount of pavers that meet the standardscould not be 80%. It is highly unlikely, almost 0, that a samplewould be the same or more extreme.b. For the pavers that meet the standard 27/51, therandomization, and the condition that more than 510 paversshould be manufactured are met. Both 27 and 24 the amountof pavers meeting the standard and not meeting the standardare over ten. The conditions are met to find the confidenceinterval.

)66.0,39.0()07.0(96.1529.0.).(*ˆ..

07.051

)529.01(529.0..529.0

51

27ˆ

ESzpIC

ESp

Remaining Free Response Answers

c. If the true proportion was 80%, then it would be near impossible tohave a sample of 27/51 that meet the standard. The confidence intervaldid not even include the 80%. The quality control specialist shouldupdate the proportion of those pavers meeting the standard.

Free Response #3

Ho:

HA: 375

375

Ho: Booker reads books that are375 pages.HA: Booker read books that are more than 375 pages.

Conclusion for #3

With a p-value of 0.08, I would fail to reject the null hypothesis. It appears that Booker does read books that average 375 pages or more. The p-value is above the 0.05 level of significance.