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Explain (a) the normal distribution and (b) the Empirical Rule. (See explanation in Empirical Rule folder at the end of module 3).
Assume that the distribution of daily sales for laptop 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 3,995 and 5,525 units?
c. What percentage of days’ sales would be expected to be more than 3,400 units?
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 be 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