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 50 and a standard deviation of 11. using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 39 and 50?

34% of lightbulb replacement requests numbering between 39 and 50.

Step-by-step explanation:

The 68-95-99.7 rule states that, for a normally distributed random variable:

68% are within 1 standard deviation of the mean(34% between one standard deviation below and the mean, 34% between the mean and one standard deviation above the mean).

95% are within 2 standard deviations of the mean.

99.7% are within 3 standard deviations of the mean.

In this problem, we have that:

The distribution of the number of daily requests is bell-shaped and has a mean of 50 and a standard deviation of 11.

Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 39 and 50?

50 is the mean

39 is one standard deviation below the mean.

This means that 34% of lightbulb replacement requests numbering between 39 and 50.

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.