Question

The sales of a grocery store had an average of $7,000 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 $7,280 per day. From past information, it is known that the standard deviation of the population is $1,000. The null hypothesis for this problem is

Answer 1

The null hypothesis for the scenario where a grocery store wants to assess the effectiveness of its advertising campaigns on its sales would be 'H0: μ = $7,000,' indicating that there is no change in the average daily sales.

Step-by-step explanation:

The problem described involves conducting a hypothesis test to see whether a grocery store's advertising campaigns have statistically significantly increased its average daily sales. The appropriate null hypothesis for this scenario, assuming we want to test for any increase in the average daily sales due to the advertising, could be stated in formal statistical terms as: H0: μ = $7,000. Here, μ represents the population mean daily sales, and $7,000 is the average sales before the advertising campaigns began.

To conduct the hypothesis test, you would use the given sample mean ($7,280), the known population standard deviation ($1,000), and the sample size (100 days). A z-test is used since the population standard deviation is known, and the sample size is large.