## The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of \$240 a

Question

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of \$240 and a standard deviation of \$25. According to the Standard Deviation Rule, in a semester, almost all (99.7%) of the students spent on textbooks in a semester:_________.

in progress 0
2 months 2021-10-13T15:41:41+00:00 1 Answer 0 views 0

1. The final part of the question is asking;

How much did all (99.7%) of the students spend on textbooks in a semester

almost all (99.7%) of the students spent between \$165 and \$315 on textbooks in a semester.

Step-by-step explanation:

The standard deviation rule describes to us that for distributions that have the normal shape, approximately 99.7% of the observations fall within 3 standard deviations of the mean.

In this question, we are given that; Mean = 240 and Standard deviation= 25

So, 3 standard deviation below the mean = Mean – 3(standard deviation)

= 240 – (3 × 25)

= 240 – 75 = 165

Now, 3 standard deviation above the mean = Mean + 3 standard deviation = 240 + (3 × 25)

= 240 + 75 = 315

So, almost all (99.7%) of the students spent between \$165 and \$315 on textbooks in a semester.