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 47 and a standard deviation of 3. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 44 and 47?

Do not enter the percent symbol.
ans =  %

Answer 1

mean = 47

sd = 3

Approx. 68% of the data lies between mean ± 1 SD, or between 41 and 47

Approx. 95% of the data lies between mean± 2 SD, or between 38 and 50

Approx. 99.7% of the data lies between mean ± 3 SD, or between 35 and 53

Approximate percentage of lightbulb replacement requests numbering between 44 and 47

As per the empirical rule 68% data is between 41 to 47.

i.e. 34% is between 41 to 44 and  34% is between 44 to 47

Approximate percentage of lightbulb replacement requests numbering between 44 and 47 is 34%

ANS: 34