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 64 days of sales was selected.It was found that the average was $8300 per day.From past information, it is known that the standard deviation of the population is $1200.The value of the test statistic is
A) .25.
B) 80.00.
C) 8.25.
D) 2.00.

Question

Quizplus · Accepted Answer

The test statistic can be calculated using the formula:
z = (x̄ - μ) / (σ / √n)
where x̄ is the sample mean, μ is the population mean, σ is the population standard deviation, and n is the sample size.
Substituting the given values, we get:
z = (8300 - 8000) / (1200 / √64)
z = 2
Therefore, the test statistic is 2.00, which is option D.

A Grocery Store Has an Average Sales of $8000 Per