Exam 10: Introduction to Estimation

If the confidence level is reduced,the confidence interval:

Draw a sampling distribution of an unbiased estimator for .

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

Given a mean of 2.1 and a standard deviation of 0.7,a 90% confidence interval will be 2.1 ± 0.7.

In order to construct a confidence interval estimate of the population mean,the value of the population mean is needed.

Other things being equal,the confidence interval for the mean will be wider for 99% confidence than for 95% confidence.

When determining the required sample size for a confidence interval,you need to know the population ____________________,the confidence ____________________,and the ____________________ on the error of estimation.

Define relative efficiency.

Conference Rooms Rented A hotel chain wants to estimate the average number of conference rooms rented daily in each month.The population of conference rooms rented daily is assumed to be normally distributed for each with a standard deviation of 24 rooms. ​ ​ -{Conference Rooms Rented Narrative} During January,a sample of 16 days has a sample mean of 48 rooms.This information is used to calculate an interval estimate for the population mean to be from 40 to 56 rooms.What is the level of confidence of this interval?

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.

The problem with relying on a point estimate of a population parameter is that:

It is intuitively reasonable to expect that a larger sample will produce more ____________________ results.

If the bound on the error of estimation decreases,the sample size ____________________.

Which of the following is not a part of the formula for constructing a confidence interval estimate of the population mean?

Suppose that a 90% confidence interval for μ is given by .This notation means that we are 90% confident that μ falls between and and

Draw a sampling distribution of a biased estimator for .

An interval estimate is an estimate of the range for a sample statistic.

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 and interpret the 99% confidence interval estimate of the population mean.

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 population standard deviation is changed to 2.

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 and interpret the 90% confidence interval estimate of the population mean.