1.Identify the type of sampling used (simple random, cluster, stratified, systematic, convenience)

a. You pick every student in 34 classes at PCC to find the mean height of PCC students.

b. You are trying to find the average income of U.S adults and you select 1,000 adults from each state.

c. In a Gallup poll of 1059 adults, the interview subjects were selected by using a computer to

randomly generate telephone numbers that were then called.

d. Police officer checked every tenth car in the college parking lot to find the average car

manufacture.

e. A student is trying to test which phones are better Apple or Samsung by asking their family.

2.Body temperatures of healthy adults have a bell shaped distribution with a mean of

98.20F and a standard deviation of 0.62F.

a. What percent of healthy adults with body temperatures within 2 standard deviation of the mean?

b. What percent of healthy adults with body temperatures greater than 98.82F.

c. What is the probability that you randomly select a healthy adult with body temperature within 97.59F 98.32F

d. If you randomly select two healthy adults and record their body temperature and the first has a z-score of -0.33 and second has a z-score of -0.35. Which adult had the warmer temperature?

3. Purchased gum Kept the money

Students give 4 quarters 29 13

Students given a $bill 11 38

a. Find the probability of randomly selecting a student who spent the money, given that the student was given four quarters.

b. Find the probability of randomly selecting a student who spent the money, given that the student was given a $1.

c. Find the probability of randomly selecting a student who kept the money, given that the student was given a $1.

4.The average IQ of adult population is 100 and are normally distributed. A researcher believes the IQ of adults is lower. A random sample of 7 adults are tested and scored: 69 , 79 , 89 , 99 , 109, 98, 81 Use a significance level of 0.05.

5.The average IQ for the adult population is 100 with a standard deviation of 15. A researcher believes this value has changed. The researcher decides to test the IQ of 84 random adults. The average IQ of the sample is 95. Is there enough evidence to suggest the average IQ has changed?