Ch.9 Business Statistics

In terms of the standard error of the mean, how wide is a 90 percent confidence interval?

2.29 Standard errors

Increasing sample size provides a more _____ of a population parameter

Accurate

What is the interval withing which a population parameter is expected to lie

Confidence interval

A confidence interval is narrower when the standard deviation ______

Decreases

What is the probability that an interval estimate include the population parameter

Degree or level of confidence

A confidence interval for a population proportion is based on using the uniform distribution to approximate the binomial distribution.

False

A point estimate is a range of values used to estimate a population parameter

False

A sample of 2000 union members was selected and their opinions regarding a proposed management union contract were recorded. 1600 members were in favor of it. A 95% confidence interval for the population proportion was computed to be 0.78 and 0.82. This indicates that about 80 out of 100 similarly constructed intervals would include the population proportion

False

An interval estimate is a singe value used to estimate a population parameter

False

An interval estimate is singe value used to estimate a population parameter

False

The finite population correction factor is used to adjust the z-statistic

False

The population variation as measured by the standard deviation has little or no effect in determining the size of a sample selected from the population

False

The statistic for a problem involving any sample size and an unknown population standard deviation is the z distribution

False

The test statistic for a problem involving any sample size and an unknown population standard deviation is the z distribution

False

The test statistic for a problem involving any sample size and an unknown population standard deviation is the z-distribution

False

To determine the value of the standard error of the mean, the total error is divided by the sample size.

False

What type of estimate states the range within which a population parameter probably lies?

Interval estimate

Other things being equal a smaller sample size would result in a wider confidence interval because the standard error of the mean is_______

Larger

To calculate the sample size required to estimate a population mean, smaller margins of error require _____ sample sizes

Larger

A sample mean is a ______ of the population mean

Point Estimate

A sample mean is a _______ of the population mean

Point estimate

A 95 percent confidence interval implies that about 95 out of 100 similarly constructed intervals will include the ______ being estimated

Population parameter or parameter

To calculate the sample size required to estimate a population mean, we must know or estimate the ________ of the population distribution

Standard Deviation

What does the t distribution approach as the sample size increases?

Standard normal Z distribution

Making generalized statements about a population based on a sample is called

Statistical inference

To compute a confidence interval, a _____ is used when the population standard deviation is unknown

T-statistic

A 95% confidence interval states that 95% of the sample means of a specified sample size selected from a population will lie within plus or minus 1.96 standard deviations of the hypothesized population mean

True

A point estimate is a singe value used to estimate a population parameter

True

An interval estimate is a range of values used to estimate a population parameter

True

One factor in determining the size of a sample is the degree of confidence selected. This is usually 0.95 or 0.99, but it may be any degree of confidence you specify

True

The finite population correction factor is applied when the population size is known

True

The t distribution is based on the assumption that the population of interest is normal or nearly normal

True

To determine the size of a sample. the standard deviation of the population must be estimated by either taking a pilot survey or by approximation is based on knowing the population

True

A confidence interval is narrower when the sample size

increases

In order to construct the 68% confidence interval, how many standard errors of the mean from the hypothesized population mean must you go?

1, or plus or minus 1 standard error

To compute a confidence interval, a ______ Is used when the population standard deviation is known.

z-statistic