# Apply: Week 4 Case

1. Determine the range of values in which you would expect to find the average weekly sales for the entire sales force in your company 90% of the time.
• Calculate the impact of increasing the confidence level to 95%.
• Calculate the impact of increasing the sample size to 150, assuming the same mean and standard deviation, but allowing the confidence level to remain at 90%.
2. Based on the calculated confidence interval for weekly sales on the sample of 50 reps at a 90% confidence level:
• Calculate both Reps’ average weekly performance and highlight if it is greater than the population mean.
3. You want to determine whether the average weekly sales between Sales Rep A and Sales Rep B are statistically different in order to decide whom to promote.
• Create Null and Alternative Hypothesis statements that would allow you to determine whether their sales performance is statistically different or not.
• Use a significance level of .05 to conduct a t-test of independent samples to compare the average weekly sales of the two candidates.
• Calculate the p-value.
4. Considering that individual you did not promote:
• Determine whether this person’s average weekly sales are greater than the average weekly sales for the 50 sales reps whose data you used to develop confidence intervals.
• Create Null and Alternative Hypothesis statements that would allow you to determine whether this person’s weekly average sales are greater than the sample of Sales Reps.
• Use a significance level of .05 to conduct a t-test of independent samples to compare the average weekly sales of both.
• Calculate the p-value.