11. You are constructing a histogram for describing the distribution of salaries for individuals who are 40 years or older, but are not yet retired.

What is on the Y-axis and X-axis?

What would be the probable shape of the salary distribution? Why?

12. Household's daily computer usage in hours is normally distributed with mean 2 and standard deviation of 0.5. What is the probability that a random household has a daily computer usage between 1.5 and 3? (Hint: You can use the Excel function NORM.DIST)

13. A test is normally distributed with a mean of 80 and a standard deviation of 15. What limits include the middle 60% of cases?