Question

The owner of a large car dealership believes that the financial crisis decreased the number of customers visiting her dealership. The dealership has historically had 800 customers per day. The owner takes a sample of 100 days and finds the average number of customers visiting the dealership per day was 750. Assume that the population standard deviation is 350. a. Specify the population parameter to be tested. b. In order to determine whether there has been a decrease in the average number of customers visiting the dealership daily, the appropriate hypotheses are _________ c. Calculate the value of the test statistic d. What is the p-value? . At the 5% significance level, what is your conclusion?

Answer 1

Answer:

a: The mean of 800 customers per day

b: See below

c: z = -1.43

d:  0.0764

e: Fail to reject the null

Step-by-step explanation:

b:  The hypotheses are:

H0: µ = 800

HA: µ < 800 (claim)

The mean number of daily customers was 800.  She feels the number of customers has decreased, so the alternate is mu is less than 800.

c:  See attached photo for the calculation of the test statistic

d:  The probability is on the z table.  Find the decimal that corresponds to the z-value of -1.43, which is: 0.0764

e: Since 0.0764 > 0.05, we fail to reject the null hypothesis.  There is not enough evidence to support the claim that the number of customers visiting the dealership has decreased.