Final answer:
The student is required to construct hypothesis tests for various statements regarding sales, training participation, call rates, and call duration. The null and alternative hypotheses are provided for each statement, along with a discussion of the hypothesis test related to average phone usage time by teenagers.
Step-by-step explanation:
The student is asking to complete hypotheses testing for different scenarios with an alpha level (significance level) of 0.05. In each case, the hypotheses can be stated as follows:
- A. For mean sales per week per salesperson, the null hypothesis (H0) is μ ≤ 42.5 and the alternative hypothesis (Ha) is μ > 42.5, where μ represents the population mean.
- B. For the proportion receiving online training, H0: p ≥ 0.55 and Ha: p < 0.55, where p represents the population proportion.
- C. For mean calls made among those with no training, H0: μ < 145 and Ha: μ ≥ 145.
- D. For mean time per call, H0: μ = 14.7 minutes and Ha: μ ≠ 14.7 minutes.
For the hypothesis test on mean time spent on the phone by teenagers, the null hypothesis would be H0: μ = 4.5 hours and the alternative hypothesis Ha: μ > 4.5 hours. Given a sample mean of 4.75 hours and a sample standard deviation of 2.0, one would perform a hypothesis test to determine if there is sufficient evidence to reject the null hypothesis at α = 0.05.
Correct Conclusion for the Hypothesis Test
The correct conclusion is that there is not enough evidence to conclude that the mean number of hours is more than 4.5 hours, as we do not have enough information about the p-value or test statistic to reject the null hypothesis at an alpha level of 0.05.