Estimation and Confidence Intervals Quiz

What is an estimator?

• A population parameter

• A statistic used to estimate a parameter

• A random variable

• A fixed value

Which estimator is considered unbiased?

• One with minimal variance

• One equal to the parameter it estimates

• One with maximum variance

• One that overestimates the parameter

What does a point estimator do?

• Estimates the range of a parameter

• Provides a single value estimate

• Determines the confidence level

• Calculates the sample size

What does a confidence interval estimate?

• The exact population parameter

• The range of possible parameter values

• The sample size needed

• The expected value of the parameter

What is the confidence level in a confidence interval?

• The likelihood that the parameter lies within the interval

• The probability that the sample mean equals the population mean

• The probability of the interval being unbiased

• The degree of variability in the sample

Which condition justifies using the normal approximation in proportion estimation?

• When both n and p are small

• When n and p are greater than five

• When the sample size is very large

• When the population variance is known

What is the margin of error in an estimate?

• The total sample size

• The maximum likely difference between the estimate and the parameter

• The population mean

• The standard deviation of the estimator

What does a sample mean estimate in a population?

• Population variance

• Population mean

• Population proportion

• Confidence level

What happens when the confidence level of an interval increases?

• The interval becomes narrower

• The interval becomes wider

• The point estimate changes

• The sample size decreases

What is required to reduce the length of a confidence interval?

• Increase the confidence level

• Increase the sample size

• Decrease the sample variance

• Increase the population size