Questions from Essentials of Statistics

Q: Must the variable under consideration be normally distributed for you to use

Must the variable under consideration be normally distributed for you to use the z-interval procedure or t-interval procedure? Explain your answer.

Q: If you obtained one thousand 95% confidence intervals for a population

If you obtained one thousand 95% confidence intervals for a population mean, μ, roughly how many of the intervals would actually contain μ?

Q: Suppose that you have obtained a sample with the intent of performing

Suppose that you have obtained a sample with the intent of performing a particular statistical inference procedure. What should you do before applying the procedure to the sample data? Why?

Q: Suppose that you intend to find a 95% confidence interval for

Suppose that you intend to find a 95% confidence interval for a population mean by applying the one-mean z-interval procedure to a sample of size 100. a. What would happen to the accuracy of the estim...

Q: A confidence interval for a population mean has a margin of error

A confidence interval for a population mean has a margin of error of 10.7. a. Obtain the length of the confidence interval. b. If the mean of the sample is 75.2, determine the confidence interval. c....

Q: Suppose that you plan to apply the one-mean z-

Suppose that you plan to apply the one-mean z-interval procedure to obtain a 90% confidence interval for a population mean, μ. You know that σ = 12 and that you are going to use a sample of size 9. a....

Q: A variable of a population has a mean of 266 and a

A variable of a population has a mean of 266 and a standard deviation of 16. Ten observations of this variable have a mean of 262.1 and a sample standard deviation of 20.4. Obtain the observed value o...

Q: We have presented a “data scenario.” In each case,

We have presented a “data scenario.” In each case, decide which type of grouping (single-value, limit, or cutpoint) is probably the best? The number of automobiles per family.

Q: Explain the meaning of each term. a. null hypothesis

Explain the meaning of each term. a. null hypothesis b. alternative hypothesis c. test statistic d. significance level

Q: Determine the critical value(s) for a one-mean

Determine the critical value(s) for a one-mean z-test at the 1% significance level if the test is a. right tailed. b. left tailed. c. two tailed.