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 42 and a standard deviation of 6. Using the empirical rule (as presented in the book), what is the approximate percentage of daily phone calls numbering between 36 and 48?

Answer 1

Solution:

Given that ,

mean = = 42

standard deviation = = 6

By using empirical rule,

- = 45 - 6 = 36

and

+ = 45 + 6 = 48

P( Between 36 and 48 ) = P( - and + )

= 34% + 34%

= 68%

The approximate percentage of daily phone calls numbering between 36 and 48 is 68%.