Instructions

1. Explain (a) the normal distribution and (b) the Empirical Rule.
2. Assume that the distribution of daily sales for laptops are normally distributed, with a mean of 4760 units and a standard deviation of 510.  Answer the following questions:

a. Between what two values would you expect 95% of the days’ sales to fall?

b. What percentage of days’ sales would be expected to fall between 1600 and 3400?

c. What percentage of days’ sales would be expected to be more than 3400?

d. What percentage of days’ sales would be expected to be more than 5500 units?

e. If you took a sample of 75 days from the previous year and found that 50 of those days had sales that ranged from 3875 to 5325 units, would that indicate a potential problem with the data?  Or would that be in line with your expectations?  Explain your rationale for your answer.

In addition, you should create a “cheat sheet” for selecting an appropriate statistical test.  Your “cheat sheet” should include information on when you would use the following tests:

• Single sample t test
• Independent samples t test
• Paired samples t test
• One-way ANOVA
• Factorial ANOVA
• ANCOVA
• Chi-Square Goodness of Fit
• Chi-Square Test of Independence
• Pearson Correlation Coefficient
• Simple Linear Regression
• Multiple Linear Regression
• Spearman rho correlation