# Question 1 The average math SAT score is 511with a standard deviation of 119. A particular…

Question 1

The average math SAT score is 511with a standard deviation of

119. A particular high school claims that its students have

unusually high math SAT scores. A random sample of 50 students from

this school was selected, and the mean math SAT score was 555. Is

the high school justified in its claim? Explain.

▼ Pick one

No

Yes

because the z-score (what is the z score)

(?)

is

▼ pick one

not unusual

unusual

since it

▼ pick one

lies

does not lie

within the range of a usual event, namely

within

▼ pick one

1 standard deviation

2 standard deviations

3 standard deviations

of the mean of the sample means

Question 2

The lengths of lumber a machine cuts are normally distributed

with a mean of 102 inches and a standard deviation of 0.4 inch.

(a) What is the probability that a randomly selected board cut

by the machine has a length greater than 102.11 inches?

(b) A sample of 43 boards is randomly selected. What is the

probability that their mean length is greater than 102.11

inches?

Question 3:

The weights of ice cream cartons are normally distributed with a

mean weight of 9 ounces and a standard deviation of 0.4 ounce.

(a) What is the probability that a randomly selected carton has

a weight greater than 9.13 ounces?

(b) A sample of 36 cartons is randomly selected. What is the

probability that their mean weight is greater than 9.13 ounces?