Question

Suppose that during an unexpected snowstorm, Mr. Wong decided to obtain a random sample of students in his AP Statistics class to examine their arrival times. He compared the difference between the students' arrival time with the time the class was supposed to begin.

Mr. Wong asks you (his assistant) to use the information below to answer the following questions (negative value means that the student arrived BEFORE class began).

Number of students	30
Mean	-1.067
Q1	-24
Q3	18
Q2	-10.5
Min	-41
Max	53
Variance	765.78850575713
Standard deviation	27.67288394344

Question A: Mr. Wong would like to determine if his students arrive to class late on average. He asks you to perform a hypothesis test @ 10% significance level. Clearly state the conclusion you would tell Mr. Wong using a critical value.

Question B:

i) Mr. Wong asks you to calculate a 90% confidence interval for the average difference in time.

ii) Interpret the interval you calculated.

iii) Based on the interval, what can you say about Mr. Wong's AP Statistics class's arrival time?

Question C: Did you expect the conclusion in Question B to be the same as the conclusion in Question A? Explain why or why not.

Answer 1