Question

In a one-tailed test, the rejection region is located under one tail (left or right) of the corresponding probability distribution, while in a two-tailed test this region is located under both tails. True False Question 8 1 pts 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 310. The value of the test statistic is Z = 1.6130 t99 = 1.6130 z = -1.6130 t99 = -1.6130

Answer 1

Ans True

The one tailed t test is used to check sample mean is either higher or lower than mean value of the population, but it is not possible to test the both together. Example: If there is a scenario to test fund manager’s performance, one tail test will be used

8)

Z (<=X) = (X – Mean)/Standard deviation of sample

X = Observed value = 800

Mean = 750

Standard deviation of population = 310

Sample size = 100

Standard deviation of sample = Standard deviation of population/sqrt(Sample size) = 310/sqrt(100) = 31

Z = (800-750)/31 = 1.6130

Ans 1.6130