# Population Standard Deviation

Pages: 3 (809 words) Published: August 18, 2011
REVIEW EXERCISES
CHAPTER 8 AND 9
PROFESSOR JONAS
WIU-RES
BY DEBRA JAMES

CHAPTER 8
1. High temperature in the United States a meteorologist claims that the average of the highest temperatures in the united states in 98. A random sample of 50 cities is selected, and the highest temperatures are recorded. The data are shown. At a=0.05 can the claim be rejected? a=7.7 97, 101, 99, 99, 100, 94, 87, 99, 108, 93, 96, 88, 98, 97,88, 105, 97, 96, 98, 102, 99, 94, 96, 114, 99, 96, 98, 97, 91, 98, 80, 95, 98, 96, 80, 95, 88, 99, 102, 95, 101, 94, 92, 99, 101, 97, 94, 97, 102, 61. The claim can be rejected; correct answer may be either above 98 or below it.

2. Salaries for Actuaries nationwide graduates entering the actuarial field earn \$40,000. A college placement officer feels that this number is too low. She surveys 36 graduates entering the actuarial field and finds the average salary to be \$41,000. The population standard deviation is \$3000. Can her claim be supported at 0.05?

x¯=14.7, μx¯=13.77, ox¯=5.34, n=29, α=.01

3. Monthly Home Rent. The average monthly rent for a one bedroom in San Francisco is \$ 1229. A random sample of 15 one bedroom homes about 15 miles outside of San Francisco had a mean rent of \$1350. The population standard deviation is \$250. At a=0.05 can we conclude that the monthly rent outside San Francisco differs from that in the city? 4.

5. Federal Prison Populations nationally 60.2% of federal prisons are severing time for drug offenses. A warden feels that in his prisons the percentage is even higher. He surveys 400 inmates records and finds that 260 of the inmates are drug offenders at a=0.05 is this correct?

CHAPTER 9
1.
Driving for pleasure - two groups of drivers is surveyed to see how many miles per week they drive for pleasure trips. The data are shown at a=0.01 can it be conducted that single drivers do more driving for pleasure trips on average than married drivers? Assume =16.7 and =16.1 Level...