Exam 7: Estimation

In a survey sample of 1000 respondents,the mean annual salary is $32,245,with a standard deviation of 4021.54.Calculate a 95% confidence interval for these data.

In a survey sample of 83 respondents,about 30.1 percent of the sample work less than 40 hours per week.Calculate a 68% confidence interval for the proportion of persons who work less than 40 hours per week.

Using the normal distribution,we know that ______ % of all random sample means will fall within ±1.96 standard errors of the true population mean.

If the level of confidence goes down (from 99% to 95%),the confidence level becomes less precise.

In a survey sample of 83 respondents,about 30.1% of the sample work less than 40 hours per week.Calculate a 68% confidence interval for the proportion of persons who work 40 hours or more per week.

If the value of the sample standard deviation increases,what happens to the confidence interval?

The actual percentage of Americans who support gay and lesbian relations is an example of a(n)

Typically,both the mean and the standard deviation of the population are unknown.

SELECT ALL THAT APPLY. -If the sample standard deviation of a sample N = 1001 is 2.60 and sample mean is 2.94,then

A point estimate is an estimate where a