Exam 10: Introduction to Estimation

A 95% confidence interval estimate for a population mean $\mu$ is determined to be 75 to 85.If the confidence level is reduced to 80%, the confidence interval for $\mu$ becomes wider.

An estimator is said to be consistent if:

We do not have control over the population standard deviation when forming a confidence interval, but we can control the ____________________ and the ____________________.

Time Spent Playing Computer Games Suppose that the amount of time teenagers spend playing computer games per week is normally distributed with a standard deviation of 1.5 hours.A sample of 100 teenagers is selected at random, and the sample mean computed as 6.5 hours. -{Time Spent Playing Computer Games Narrative} Interpret the 95% confidence interval for this situation.

Determine the sample size that is required to estimate a population mean to within 0.4 units with a 99% confidence when the population standard deviation is 1.75.

The difference between the sample statistic and actual value of the population parameter is the confidence level of the estimate.

The version of the sample variance where you divide by ____________________ gives you an unbiased estimator of the population variance.

The sample variance (where you divide by n - 1) is an unbiased estimator of the population variance.

The sample variance s² is an unbiased estimator of the population variance $\sigma$ ² when the denominator of s² is

A specific confidence interval obtained from data will always correctly estimate the population parameter.

Explain briefly why interval estimators are preferred to point estimators.

The width of a confidence interval estimate of the population mean increases when the:

MN -{Conference Rooms Rented Narrative} During February, a sample of 25 days has a sample mean of 37 rooms.Use this information to calculate a 92% confidence interval for the population mean.

Which of the following statements is correct?

An unbiased estimator is said to be consistent if the difference between the estimator and the parameter grows larger as the sample size grows larger.

The value for a 95% confidence interval estimate for a population mean $\mu$ is

The sample ____________________ is an unbiased estimator for the population mean.

Which of the following is a characteristic for a good estimator?

An unbiased estimator is said to be consistent if the difference between the estimator and the parameter grows smaller as the sample size grows larger.

Time Spent Playing Computer Games Suppose that the amount of time teenagers spend playing computer games per week is normally distributed with a standard deviation of 1.5 hours.A sample of 100 teenagers is selected at random, and the sample mean computed as 6.5 hours. -{Time Spent Playing Computer Games Narrative} Determine the 95% confidence interval estimate of the population mean if the sample mean is changed to 5.0 hours.