Probability and Statistics

Question

In a mid-size company, the distribution of the number of phone calls answered each day by each of the 12 receptionists is bell-shaped and has a mean of 62 and a standard deviation of 7. Using the empirical rule, what is the approximate percentage of daily phone calls numbering between 55 and 69?

Answer 1

roughly 2/3 of the data lies within 1 standard deviation of the mean.

 

 62 +or- 7 = (55,69)

 

roughly 2/3 of the data ...

66 and 2/3%

Some texts say 67% or 68%