3. The Martha's Vineyard Legal Studies Center is interested in the extent to which practicing attorneys in Massachusetts perform pro bono work. They survey a random sample of 200 attorneys, asking how many hours they typically spend on pro bono activity during a typical work week. These are the results:

Hours f

0 47

1 64

2 36

3 29

4 17

5 9

Total 200

a. (3 points) Find the mode, median, mean, and standard deviation for pro bono hours.

b. (2 points) Estimate the mean number of hours for all Massachusetts practicing attorneys with 95% confidence.

c. (1 point) According to the American Bar Association, there are 43,974 attorneys in Massachusetts. What would you project is the total number of pro bono hours performed weekly by attorneys in Massachusetts?

d. (1 point) The population of Massachusetts stands at 6,794,422. How many attorneys are there per 10,000 population?