Question

The manager of a grocery store has taken a random sample of 100 customers to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes. She observes that the average length of time it took the customers in the sample to check out was 3.1 minutes. The population standard deviation is known to be 0.5 minutes.

USE INFORMATION TO ANSWER THE FOLLOWING:

1A. What is the appropriate test to use for this problem?

A) Two sample z-test

B) Two sample t-test

C) One sample z-test

D) One sample t-test

1B. What is the observed value of your test statistic?

A) 1.64

B) 2.00

C) 0.056

D) 1.96

1C. What is the corresponding p-value?

A) 0.05

B) 0.0456

C) 0.025

D) 0.0228

1D) At 5% level of significance what is your conclusion?

A) Accept the null hypothesis

B) Reject the alternate hypothesis

C) Not reject the null hypothesis

D) Reject the null hypothesis

Answer 1

C) One sample z-test

This is the right tailed test .

The null and alternative hypothesis is

H₀ : = 3

H_a : > 3

Test statistic = z

= ( - ) /    / n

= (3.1 - 3) / 0.5 / 100

Test statistic = 2.00

P-value = 0.0228

P-value <

D) Reject the null hypothesis