The sales of a grocery store had an average of $8,000 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 64 days of sales was selected. It was found that the average was $8,250 per day. From past information, it is known that the standard deviation of the population is $1,200.

The value of the test statistic is:.

The value of the test statistic is 1.667

Step-by-step explanation:

We are given that the sales of a grocery store had an average of $8,000 per day. The store introduced several advertising campaigns in order to increase sales. For this a random sample of 64 days of sales was selected. It was found that the average was $8,250 per day. From past information, it is known that the standard deviation of the population is $1,200.

We have to determine whether or not the advertising campaigns have been effective in increasing sales.

Let, Null Hypothesis, : = $8,000 {means that the advertising campaigns have not been effective in increasing sales}

Alternate Hypothesis, : > $8,000 {means that the advertising campaigns have been effective in increasing sales}

The test statistics that will be used here is One sample z-test statistics;

             T.S. = ~ N(0,1)

where, Xbar = sample mean = $8,250

                 = population standard deviation = $1,200

                 n = sample size = 64

So, test statistics =

                            = 1.667

Therefore, the value of test statistics is 1.667 .

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step-by-step explanation: