question 12

Find the area of the indicated region under the standard normal curve.

A normal curve is over a horizontal z-axis and is centered on 0. Vertical line segments extend from the horizontal axis to the curve at 0 and 0.7. The area under the curve between 0 and 0.7 is shaded.

The area between z=0 and z=0.7 under the standard normal curve is ____

(Round to four decimal places asneeded.)

question 13

Find the probability and interpret the results. Ifconvenient, use technology to find the probability. During a certain week the mean price of gasoline was $2.706 per gallon. A random sample of 36 gas stations is drawn from this population. What is the probability that the mean price for the sample was between $2.698 and $2.718 thatweek? Assume =$0.047.

The probability that the sample mean was between $2.698 and $2.718 is _____

(Round to four decimal places asneeded.)

Interpret the results. Choose the correct answer below.

A.

About 22% of samples of 36 gas stations that week will have a mean price between$2.698 and $2.718.

B.

About 22% of the population of 36 gas stations that week will have a mean price between$2.698 and $2.718.

C.

About 78% of samples of 36 gas stations that week will have a mean price between$2.698 and $2.718.

D.

About 78% of the population of 36 gas stations that week will have a mean price between$2.698 and $2.718.

question 14

Use the central limit theorem to find the mean and standard error of the mean of the indicated sampling distribution. Then sketch a graph of the sampling distribution.

The per capita consumption of red meat by people in a country in a recent year was normallydistributed, with a mean of 105 pounds and a standard deviation of 37.2 pounds. Random samples of size 17 are drawn from this population and the mean of each sample is determined.

x=

x=

(Round to three decimal places asneeded.)

question 16

A vending machine dispenses coffee into atwenty-ounce cup. The amount of coffee dispensed into the cup is normally distributed with a standard deviation of 0.02 ounce. You can allow the cup to overfill 4% of the time. What amount should you set as the mean amount of coffee to bedispensed?______ ounces

(Round to two decimal places asneeded.)

question 18

Find the area of the indicated region under the standard normal curve.

The area between z=1.3 and z=0.7 under the standard normal curve is

________

(Round to four decimal places asneeded.)