You manage Human Relations for your company. One of your sales managers has retired, leaving an opening. You are considering two different employees for the position. Both are highly qualified so you have decided to evaluate their sales performance for the past year.
Use the Week 4 Data Set to create and calculate the following in Excel®:
- 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. (re-watch the Excel 2007 video on calculating a confidence interval)
- 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%.
- 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.
- 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. Use a t test in Data Analysis Toolpak. Select the option for unequal variance.
- 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.
- 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. Should you accept or reject the null hypothesis.