20.Running times in a daily workout have a mean of 36 minutes and a standard deviation of 7 minutes. The distribution is unknown. Using Chebyshev's Rule, in what interval about the mean would you expect to find at least 75% of the workout times?

Interval is-

35.Test grades are skewed left with a mean of 72 and a standard deviation of 5. Using Chebyshev's Rule, in what interval about the mean would you expect to find at least 94% of the grades?

Interval is -

39 In a mid-size company, the distribution of the number of phone calls answered each day by each of the 12 receptionists is not bell-shaped and has a mean of 58 and a standard deviation of 11. Using Chebyshev's Rule, at least what percentage of daily phone calls number between 36 and 80?

Percentage is %