Chapter 7 Review

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election. Which of the following statements is true about the boldface numbers?

• 72% is a population and 56% is a sample
• 72% is a parameter and 56% is a statistic
• 72% is a sample and 56% is a population
• 72% is a statistic and 56% is a parameter

Tags

CCSS.HSS.IC.B.3

Which of the following statements is false?

• Parameters describe population characteristics
• Statistics describe sample characteristics
• The sample is a subset of the population
• Statistics must be based on simple random samples

You take an SRS of size 500 from the 37,000 students at Purdue University and measure individual’s heights. You then take an SRS of size 500 from the 4,400,000 adults in the state of Indiana and measure their heights.  Which sampling distribution would have the smaller standard deviation?

• Purdue because the sample is a larger percent of the population.
• Indiana because the sample size is a smaller percent of the   population.
• They would have the same standard deviation because they are the same sample size.
• You cannot compare because the samples are from different   populations.

Above are dot plots estimating the same parameter (marked with an arrow) in 30 samples from the same population.  Which distribution cannot be classified as an unbiased estimator of the parameter?

• A only
• B only
• C only
• B and C

Above are dot plots estimating the same parameter (marked with an arrow) in 30 samples from the same population.  Which distribution has the largest sample size?

• A only
• B only
• C only

Above are dot plots estimating the same parameter (marked with an arrow) in 30 samples from the same population.  Which distribution is the preferred estimator for the parameter?

• A only
• B only
• C only

Which of the following produces an unbiased estimator?

• using simple random samples
• using smaller sample sizes
• using larger sample sizes
• using an average, not a percent

Which of the following reduces the variability of estimates?

• using simple random samples
• using smaller sample sizes
• using larger sample sizes
• using an average, not a percent

A recent poll showed 82% of Tennesseans own a pet.  Suppose your took an SRS of 50 Tennesseans and asked if they owned a pet.  Does the sampling distribution pass the Normal condition?

• Yes because n > 30
• Yes because np > 10
• No because n(1 – p) > 10
• No because the population in not Normal

The central limit theorem ensures that as long as the sample size is greater than or equal to 30.

• the population will be Normally distributed
• the sampling distribution of the sample proportion ("p-hat") will be Normally distributed
• the sampling distribution of the sample mean ("x-bar") will be Normally distributed
• that all distributions will be Normal