1) On a standardized aptitude test, scores are normally distributed with a mean of 100 and a standard deviation of 10. Find the PERCENT of scores that are:

A) Between 90 and 100.

B) Over 110

C) Between 80 and 120

D) Less than 80

E) Between 70 and 100

F) More than 130

A) 34.13%

B)  15.87%

C) 95.44%

D) 97.72%

E) 49.87%

F) 0.13%

Step-by-step explanation:

To find the percent of scores that are between 90 and 100, we need to standardize 90 and 100 using the following equation:

Where m is the mean and s is the standard deviation. Then, 90 and 100 are equal to:

So, the percent of scores that are between 90 and 100 can be calculated using the normal standard table as:

P( 90 < x < 100) = P(-1 < z < 0) = P(z < 0) - P(z < -1)

                                                =  0.5 - 0.1587 = 0.3413

It means that the PERCENT of scores that are between 90 and 100 is 34.13%

At the same way, we can calculated the percentages of B, C, D, E and F as:

B) Over 110

C) Between 80 and 120

D) less than 80

E) Between 70 and 100

F) More than 130

answer: 0+0=0

step-by-step explanation:

that is the only answer that can make 0

step-by-step explanation: