Statistics assessment

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 39 and a standard deviation of 7. Using the empirical rule,what is the approximate percentage of daily phone calls numbering between 18 and 60

Answer 1

from z=-2 to z =3

= 95/2+99.7/2

=47.5+49.85

= 97.35%