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 49 and a standard deviation of 7. Using Chebyshev's Rule, at least what percentage of daily phone calls number between 21 and 77? Percentage is =

40.Weights of Old English Sheepdogs are normally distributed with a mean of 59 pounds and a standard deviation of 7 pounds. Using the Empirical Rule, what is the approximate percentage of sheepdogs weighing between 52 and 66 pounds?

43.A child's piano practice times are normally distributed with of 18 minutes and a standard deviation of 4 minutes. Using the empirical rule, in what interval about the mean would you expect to find 68% of the practice times?

Interval is-