If you are constructing a confidence interval for a population mean, for the same confidence level, the width of the confidence interval will __________ as the sample size increases.
Decrease
Increase
Stay the same
Depends on the sample size
as widht of confidence interval is inversely proportional to square root of sample size
hence decrease
If you are constructing a confidence interval for a population mean, for the same confidence level,...
The larger the confidence level used in constructing a confidence interval estimate of the population mean, the wider the confidence interval. True False
Which of the following correctly describes how the width of a confidence interval for a population mean changes when the population standard deviation is known? There is no change if just the sample size increases. The interval widens if the sample size stays the same and confidence level decreases. The interval narrows if the sample size increases and confidence level stays the same. The interval narrows if the sample size decreases and confidence level stays the same. The interval widens...
QUESTION 1 In constructing a 95% confidence level estimate of the mean when the population standard deviation () is known what will be your score used in the formula? QUESTION 2 In constructing a 99% confidence level estimate of the mean when the population standard deviation (a) is known what will be your score used in the formula? HINT. Be sure to review page 236 "Finding Z scores from Known Areas - Special Cases and Tabel A-2. QUESTION 3 In...
Please show the process 6. In developing an interval estimate for a population mean, the population standard deviation σ was assumed to be 10. The interval estimate was 50.92 2.14. Had ơ equaled 20, the interval estimate would be a. 60.92 t 2.14 b. 50.92 12.14 c. 101.84 4.28 d. 50.92t 4.28 7. If the confidence level is reduced, the confidence interval a. widens. b. remains the same. C. narrows. d. disappears. 8. The zal value for a 95% confidence...
True or False? The higher the confidence level, the narrower is the confidence interval for the mean. Select an answer The most efficient point estimator for the population mean ù is the sample median . Select an answer • To reduce the width of a confidence interval, we can increase the sample size n. Select an answer • As long as the population is normal with variance o’, the statistic (n-1) S2 has a Chi-squared 02 distribution with n degrees...
Consider the usual confidence interval for the mean of a normal population with known variance. What is the relationship between confidence and precision as measured by interval width? A. For a fixed sample size, decreasing the confidence level has no effect on the precision B. For a fixed sample size, decreasing the confidence level decreases the precision C. For a fixed sample size, decreasing the confidence level increases the precision D. None of the above
Suppose we have an existing confidence interval for a population mean. If we increase the sample size by a factor of 100, what happens to the width of the confidence interval? a) It remains the same. b) It decreases by a factor of 100. c) It increases by a factor of 10. d) It decreases by a factor of 10.
Suppose you wish to estimate the mean of a normal population using a 95% confidence interval, and you know from prior information that σ2 ≈ 1. a. To see the effect of the sample size on the width of the confidence interval, calculate the width of the confidence interval for n = 16, 25, 49, 100, and 400. b. Plot the width as a function of sample size n on graph paper. Connect the points by a smooth curve and...
You want to estimate the population mean by taking a sample and constructing a 80% confidence interval. You know the population standard deviation is 6.08. Compute the minimum sample size needed to ensure that your interval estimate has a margin of error less than or equal to 1.8.
Confidence Intervals 9. Construct a 95 % confidence interval for the population mean, . In a random sample of 32 computers, the mean repair cost was $143 with a sample standard deviation of $35 (Section 6.2) Margin of error, E. <με. Confidence Interval: O Suppose you did some research on repair costs for computers and found that the population standard deviation, a,- $35. Use the normal distribution to construct a 95% confidence interval the population mean, u. Compare the results....