Exam 8: Interval Estimation

From a population that is normally distributed, a sample of 25 elements is selected and the standard deviation of the sample is computed.For the interval estimation of μ, the proper distribution to use is the

The probability that the interval estimation procedure will generate an interval that does not contain the actual value of the population parameter being estimated is the​

In a random sample of 144 observations, $\bar { p }$ = .6.The 95% confidence interval for p is

A random sample of 25 employees of a local company has been taken.A 95% confidence interval estimate for the mean systolic blood pressure for all employees of the company is 123 to 139.Which of the following statements is valid?

A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22.The population standard deviation is known to equal 4.8.The 95.44% confidence interval for the population mean is

For the interval estimation of μ when σ is known and the sample is large, the proper distribution to use is the

To compute the necessary sample size for an interval estimate of a population proportion, all of the following procedures are recommended when p is unknown except​

In interval estimation, as the sample size becomes larger, the interval estimate

The manager of a grocery store has taken a random sample of 100 customers.The average length of time it took these 100 customers to check out was 3 minutes.It is known that the standard deviation of the population of checkout times is 1 minute.The standard error of the mean equals

The t value for a 95% confidence interval estimation with 24 degrees of freedom is

In developing an interval estimate, if the population standard deviation is unknown

A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00.If we want to determine a 95% confidence interval for the average hourly income of the population, the value of t is

In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determined.Assume a population standard deviation of 450 kilowatt-hours.The standard error of the mean is

The mean of the t distribution is​

In a random sample of 100 observations, $\bar { p }$ = .2.The 95.44% confidence interval for p is

A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00.The value of the margin of error at 95% confidence is

From a population that is not normally distributed and whose standard deviation is not known, a sample of 6 items is selected to develop an interval estimate for the mean of the population (μ).

In a sample of 400 voters, 360 indicated they favor the incumbent governor.The 95% confidence interval of voters not favoring the incumbent is

We can reduce the margin of error in an interval estimate of p by doing any of the following except​

It is known that the population variance equals 484.With a .95 probability, the sample size that needs to be taken if the desired margin of error is 5 or less is