A school administrator wants to see if there is a difference in the number of students per class for the Portland Public School district (Group 1) compared to the Beaverton School district (Group 2). Let μ1 be the average number of students per class for the Portland Public School district. Let μ2 be the average number of students per class for the Beaverton School district. Assume the populations are normally distributed. A random sample of 28 Portland classes found a mean of 35 students per class with a standard deviation of 5. A random sample of 27 Beaverton classes found a mean of 32 students per class with a standard deviation of 4.  Find a 99% confidence interval for the difference of the means. Use Excel Two Means Calculator and round answers to 2 decimal places. ________ < μ1-μ2 < _______ Since the above confidence interval (select: Contains a zero, Is positive, Is negative) _________     , with 99% confidence, it is plausible that the average number of students per class for the Portland Public School district is (Select: Same as,  Smaller than, Hight than)__________    that for the Beaverton School district.

College Algebra (MindTap Course List)
12th Edition
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:R. David Gustafson, Jeff Hughes
Chapter8: Sequences, Series, And Probability
Section8.7: Probability
Problem 6E: List the sample space of each experiment. Tossing three coins
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A school administrator wants to see if there is a difference in the number of students per class for the Portland Public School district (Group 1) compared to the Beaverton School district (Group 2).

Let μ1 be the average number of students per class for the Portland Public School district.
Let μ2 be the average number of students per class for the Beaverton School district. Assume the populations are normally distributed.

A random sample of 28 Portland classes found a mean of 35 students per class with a standard deviation of 5.
A random sample of 27 Beaverton classes found a mean of 32 students per class with a standard deviation of 4. 

  1. Find a 99% confidence interval for the difference of the means. Use Excel Two Means Calculator and round answers to 2 decimal places.

    ________ < μ1-μ2 < _______



  2. Since the above confidence interval (select: Contains a zero, Is positive, Is negative) _________     , with 99% confidence, it is plausible that the average number of students per class for the Portland Public School district is (Select: Same as,  Smaller than, Hight than)__________    that for the Beaverton School district.
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