Question

The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of 434 and a standard deviation of 31. According to the standard deviation rule, approximately 99.7% of the students spent between ____$ and ______$ on textbooks in a semester.

Question 12

Type numbers in the boxes.

1 points

The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 15. According to the standard deviation rule, _____% of people have an IQ between 55 and 145. Do not round.

Question 13

Type numbers in the boxes.

10 points

The distribution of IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 16. According to the standard deviation rule, only
______% of people have an IQ over 132.

Question 14

Type numbers in the boxes.

10 points

The distribution of the amount of money spent by students on textbooks in a semester is approximately normal in shape with a mean of: μ= 473 and a standard deviation of: σ= 37.

According to the standard deviation rule, almost 16% of the students spent more than what amount of money on textbooks in a semester? ______

Answer 1

Solution :

Given that,

= 434

= 31

Using Empirical rule,

P( - 3< X < + 3) = 99.7%

P(434 - 3 * 31 < X < 434 + 3 * 31) = 99.7%

P(341 < X < 527) = 99.7%

According to the standard deviation rule, approximately 99.7% of the students spent between $ 341 and $ 527

on textbooks in a semester .