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 55 and a standard deviation of 3. Using the empirical rule, what is the approximate percentage of daily phone calls numbering between 52 and 58?

Answer 1

The answer is very simple. .

Applying the empirical rule involves following the steps:

Construct the intervals of the rule

Since the mean is 55 and the standard deviation is 3, then the intervals are:

[µ – s, µ + s] = [55 – 3, 55 + 3] = [52, 58]

The empirical rule defines the following intervals:

68.27% of the data are in the interval: [µ - s, µ + s]

The answer is:

The approximate percentage of daily phone calls is 68.27 %