Chapter 8: Interval Estimation

the most typical form of the confidence interval for a population parameter is

[point estimate - margin of errors, point estimate + margin of errors]

the ability of an interval estimate to contain the population parameter is described by

the confidence level

whenever the population standard deviation sigma is unknown and the population has a normal or near-normal distribution, which of the following distributions is used in developing an interval estimate for the population mean?

t distribution

Why are 95% and 99% confidence intervals are different

as the confidence level increases, the confidence interval gets wider

as the number of degrees of freedom of the t distribution increases, the difference between he t distribution and the standard normal distribution

becomes smaller

for a given sample size and population or sample standard deviation, which of the following is true in the interval estimation of the population mean

if the confidence level is greater, the confidence interval is wider

for a given confidence level and population or sample standard deviation, which of the following is true in the interval estimation of the population mean

if the sample size is greater, the confidence interval is narrower

after finding a confidence interval for the population mean, the user believers the result is meaningless because the interval is too wide. which one of the following is the best recommendation

increase the sample size

An estimate of a population parameter that provides an interval of values believed to contain this parameter is known as the

interval estimate

the value added and subtracted from a point estimate in order to develop an interval estimate of the population parameter is known as the

margin of error

in order to use the normal distribution for interval estimation of the population mean mu, when the population standard deviation sigma is known and the sample is small, the population must have

normal distribution

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

t distribution with 24 degrees of freedom

for the interval estimation of the population mean mu, when the population standard deviation sigma is known and the sample is sufficiently large, the proper distribution to use is

the normal distribution