A grocery store has an average sales of $8000 per day. The store introduced several advertising campaigns in order to increase sales. To determine whether or not the advertising campaigns have been effective in increasing sales, a sample of 100 days of sales was selected. It was found that the average was $8200 per day. From past information, it is known that the standard deviation of the population is $1500. The value of the test statistic is
A) .013.
B) .133.
C) 13.33.
D) 1.33.

Question

Quizplus · Accepted Answer

We can use a one-sample t-test to determine if the increase in sales is statistically significant. The formula for the t-test is:

t = (sample mean - population mean) / (standard deviation / sqrt(sample size))

Plugging in the values given:

t = (8200 - 8000) / (1500 / sqrt(100))
t = 200 / 150
t = 1.33

The value of the test statistic is 1.33, which is option D.

A Grocery Store Has an Average Sales of $8000 Per