1) In a certain state, 45% of 400 workers belonged to a union.Construct a 95% confidence interval for the proportion of all workers in the state that belong to a union using error notation.

.55 .0366

(.069, .111)

(.511, .589)

.55 .04361

.45 .04875

2) Identify the margin of error for the following confidence interval for p

(.250, .650)

0.8

.45

.20

0.4

0.90

3)A researcher is interested in estimating the average age of a police officer in a large city.She wants to be 95% confident that her estimate is correct.The population standard deviation is $1050.How large a sample is necessary to get the desired confidence level and be accurate to within $200?

75

97

106

48

189

4) A random sample of 2000 U.S. homes found that 25% had a satellite system.How large a sample is necessary to estimate the proportion of U.S. homes that have a satellite system with 95% confidence and be within 3%.

564

201

1068

141

801

5)A researcher hypothesizes that the average wind speed in Chicago Illinois is greater than 24 mph.What is the correct Alternate Hypothesis?HA

HA: 24

HA: < 24

HA: 24

HA: > 24

HA: 24

6)A tire company claims that their best value tire lasts at least 50,000 miles.In conducting a test of hypothesis to test this claim, which is the correct null hypothesis?

HA: 50000

H0: > 50000

H0: 50000

HA: > 50000

H0: < 50000