The quiz grades of a class are: 79, 89, 97, 64, 79, 80, 5278, 58, 89, 71, 65, 96, 7785, 90, 67, 77, 100, 88, 7666, 68, 84, 79, 72, 70, 67

Answer the following questions. Please show your work.

1. What is the median?

2. What is the mode?

3. What is the range?

4. What is the mean?

5. What is the variance?

6. What is the standard deviance? --

Assume that the grades are arranged into 5 groups: 50-59, 60-69, 70-79, 80-89 and 90-100.

7.Construct the grouped frequency table.

8.Plot the histogram of the grouped frequency distribution.

9.Plot the histogram of the grouped relative frequency distribution.

10.We selected 5 class intervals to represent the grades. Was it appropriate? Please use the Sturgess rule and the Rices rule to explain.