AP stat chapter 8 EC quiz

confidence level

• tells how close the estimate tends to be to the unknows parameter in repeated random sampling

• the success rate of the method that produces the confidence interval.

• the specific value of a point estimator

• a statistic that provides an estimate of a population parameter

point estimator

• a statistic that provides an estimate of a population parameter

• the specific value of a point estimator

• describes how far mean x will be from u.

• tells how close the estimate tends to be to the unknown parameter in repeated random sampling.

confidence interval

• obtained from the sampling distribution

• gives overall success rate of the method for calculating the confidence interval.

• gives an interval of plausible values for a parameter.

• a multiplier that makes the interval wide enough to have the stated capture rate

critical value

• a multiplier that makes the interval wide enough to have the stated capture rate.

• gives an interval of plausible values for a parameter

• gives the overall success rate of the method for calculating the confidence interval

• statistic that provides an estimate of a population parameter

standard error

• when the standard deviation of a statistic is estimated from data

• based on the sample mean of an SRS

• uses sample data to estimate an unknown population parameter

• success rate of the method that produces the interval.

One reason for using t distribution instead of the standard normal curve to find critical values when calculating a level C confidence interval for a population mean is that

• z can be used only for large samples

• z requires that you know the population standard deviation

• z requires that you can regard your data as an SRS from the population

• z requires that the sample size is at most 10% of the population size.

A quality control inspector will measure the salt content in a random sample of bags of potato chips from an hors of production. Which of the following would result in the smallest margin of error in estimating the mean salt content.

• 90 percent confidence; n-25

• 90 percent confidence; n=50

• 95 percent confidence; n=25

• 95 percent confidence; n=50

The Gallup poll interviews 1600 people. of these, eighteen percent say that they jog regularly. the new report adds: " The poll had a margin of error of plus or minus three percentage points at a 95 percent confidence level." You can safely conclude that

• 95 percent of all Gallup Poll samples like this one give answers within three percent of the true population valve.

• the percent of the population who jog is certain to be between 15 percent and 21 percent.

• 95 percent of the population jog between 15 and 21 percent of the time

• we can be 95 percent confident that the sample proportion is captured by the confidence interval.

The weights in pounds of three adult males are 160,215, and 195. The standard error of the mean of these three weights is.

• 190

• 27.84

• 22.73

• 16.07

In preparing to construct a one-sample t interval for a population mean, suppose we are not sure if the population distribution is Normal. IN which of the following circumstances would we not be safe constructing the interval based on an SRS of size 24 from the population

• A stemplot of the data is roughly bell shaped

• a histogram of the data shows slight skewness

• a boxplot of the data has a large outlier

• the sample standard deviation is large.