Proportions Based on Samples

If no p-hat value is given, what should you assume p-hat equals?

• 0.01

• 0.05

• 0.10

• 0.5

Which of the following hypotheses is a valid example of a 1-tailed test?

• Ho: p = 0.3, Ha: p > 0.4

• Ho: p = 0.3, Ha: p ≠ 0.3

• Ho: p^ = 0.3, Ha: p^ > 0.3

• Ho: p = 0.3, Ha: p > 0.3

Two confidence interval estimates from the same sample are (0.72, 0.83) and (0.75, 0.81). One is at 95%, the other is at 99%. Which is which?

• (0.72, 0.83) is at 99%

• (0.72, 0.83) is at 95% 

• Need to know sample size to determine this

• Need to know standard error to determine this

A credit card company would like to compare the proportion of people who have poor credit to the proportion of people who think they have poor credit. Which of the following is most appropriate?

• Proportion Z-Test

• Proportion Z-Interval

• 2-Proportion Z-Test

• 2-Proportion Z-Interval

Define the symbol.

• population proportion

• population standard deviation

• sample proportion

• sample size

Define the symbol.

• sample size

• standard deviation of sampling distribution of sample means

• population proportion

• sample proportion

Match the following

• x

• The population proportion

• p

• The Sample Proportion

• p̂

• The Sample Size

• n

• The number of individuals in the sample with the specific trait

Select the correct description

• Average Percent

• Population Proportion

• Sample Proportion

• Percent Slope of a Distribution

A 99% confidence interval found that the true proportion of teens who drink coffee every day is in the interval (0.785, 0.831). What was the p^ value used to determine this interval? 

• 0.8

• 0.808

• 0.825

• 0.831

Which of the following is true pertaining to a 2-proportion z-interval?

• There are no restrictions on sample size 

• This interval can be found even if the samples are not random

• The population should be large, relative to each of the sample sizes

• So long as all conditions are met for one sample, you do not need to check conditions for the other sample