Question

The Rocky Mountain district sales manager of Rath Publishing Inc., a college textbook publishing company, claims that the sales representatives make an average of 38 sales calls per week on professors. Several reps say that this estimate is too low. To investigate, a random sample of 38 sales representatives reveals that the mean number of calls made last week was 40. The standard deviation of the sample is 2.2 calls. Using the 0.100 significance level, can we conclude that the mean number of calls per salesperson per week is more than 38?

H0 : μ ≤ 38

H1 : μ > 38

1. Compute the value of the test statistic. (Round your answer to 3 decimal places.) Value of the test statistic

2. What is your decision regarding H0? H0. The mean number of calls is than 38 per week.

Answer 1

Solution: 1. Compute the value of the test statistic.

Answer: We are given:

The test statistic is given below:

  

  

Therefore, the test statistic is

2. What is your decision regarding H0? The mean number of calls is than 38 per week.

Answer: The right tailed t critical value at 0.10 significance level for is given below:

Since test statistic is greater than t critical value, we therefore reject the null hypothesis.

The decision regarding H0 is to Reject it and conclude that the mean number of calls is greater than 38 per week.