Question

The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 57 and a standard deviation of 7. Using the empirical rule (as presented in the book), what is the approximate percentage of lightbulb replacement requests numbering between 50 and 57

Answer 1

34%

Explanation:

According to the empirical rule, 68% of all of the data in a normal distribution falls within one standard deviation of the mean.

Applying to this particular case, 68% of the requests fall within (50 - 7) and (50+ 7). The percentage of requests from 43 to 50 is equal to the percentage of requests from 50 to 57.

Therefore, the percentage of light bulb replacement requests numbering between 50 and 57 is 68/2 = 34%.