Question

The physical plant at the main campus of a large state university receives daily requests to replace fluorescent light bulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 63 and a standard deviation of 6. Using the 68-95-99.7 rule, what is the approximate percentage of light bulb replacement requests numbering between 63 and 75?

Answer 1

In this case, we'll have to carry out several steps to find the solution.

Step 01:

Data:

mean = 63

standard deviation = 6

Step 02:

distribution (bell-shaped):

68-95-99.7 rule:

63 to 75:

63 + σ = 63 + 6 = 69 ===> 34%

63 + 2σ = 63 + 2*6 = 63 + 12 = 75 ===> 34% + 13.5% = 47.5%

The answer is:

47.5%