Question

Eric wonders how many people shop at Trader Joe’s every day during the quarantine. Since he is supposed to be inside, he randomly selects 30 days to go and measure how many people shop at Trader Joe’s. Over these 30 days, he finds that the average number of shoppers is 94.6 and the standard deviation is 16. Note you do not know the true population standard deviation!

a) Based on the information provided, do you need to apply the Central Limit Theorem, and can you apply it?

b) Construct a 95% confidence interval for the mean number of people who shop at Trader Joe’s, and interpret it.

c) Suppose Eric wants to test if less than 100 people shop at Trader Joe’s per day, at a significance level of .05. What are the hypotheses for this test?

d) Calculate the t-test statistic for the test defined in part (c).

e) Find the P-value for the test Eric is conducting.

f) Make your conclusion for the hypothesis test and interpret its meaning in the context of the problem

Answer 1