100 juniors at a nearby private school took the act test.
the scores were distributed normally with a mean of 22 and a standard deviation of 3

what percentage of scores are between 22 and 25?

what percentage of scores are between 16 and 28

what percentage is less than 13

what percentage is greater than 25

approximately how many juniors scored higher than 22

and lastly how many juniors scored between 19 and 25

I'll be using the empirical (68-95-99.7) rule extensively. It also helps to know that the normal distribution with mean and standard deviation is symmetric about its mean.

a.

b.

c.

d.

e. , so about 50 juniors scored above the average.

f. , so about 68 juniors scored between 19 and 25.

see below

step-by-step explanation:

7.   there are 10 data points in the set.   the middle point is between 5 and 6.   the middle point in the top half is 8   and the middle point in the bottom half is 3. to find the iqr , take point 8 and subtract point 3

mid term   point 8 = 100   point 3 = 88

iqr = 100-88 = 12

final   point 8 = 93   point 3 = 78

iqr = 93 - 78 = 15

the final has the greatest iqr

6.   b - there is a high data value that causes the data set to be asymmetrical for the males: the data for males are high and asymmetrical .   there is an outlier for the males that skews the data

5.   the   iqr is a better measure of spread for the movies and basketball games.   since the basketball game has an outlier, we do not want to use standard deviation for measurement.  

3.   the exam median is much higher than the class median.   the median line is farther to the right on the exams

2.   there is no way to tell what the means are from the box and whisker plots.