Describe how the width of a 95% confidence interval for a mean changes as the sample size (n) increases, assuming the standard deviation remains the same. As the sample size increases, the width of a 95% confidence interval for a mean gets , assuming the standard deviation remains the same.
Choices are
larger, gets smaller, gets larger, stays the same
Describe how the width of a 95% confidence interval for a mean changes as the sample...
Which of the following does NOT correctly describe how the width of a confidence interval for a population mean changes when the population standard deviation is known? The interval changes if the sample size decreases. The interval changes if the sample size increases. The interval narrows if the sample size increases and confidence level stays the same. The interval widens if the sample size decreases and the confidence level stays the same. The interval widens if the sample size stays...
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...
Find the margin of error for a 95% confidence interval for estimating the population mean when the sample standard deviation equals 92, with a sample size of (a) 400,(b) 1800. What is the effect of the sample size? 2. The margin of error for a 95% confidence interval with a sample size of 400 is (Round to the nearest tenth as needed.) b. The margin of error for a 90% confidence interval with a sample size of 1600 is (Round...
QUESTION 3 All things being equal, which is correct? As the confidence level increases, the margin of error gets larger. As the sample size increases, the confidence interval gets wider. As the standard deviation increases, the margin of error gets smaller. As the sample mean increases, the margin of error gets larger. Which of the following is correct? As the sample size increases, the confidence level decreases. As the confidence level increases, the width of the confidence interval decreases. As...
Consider the formula for estimating a population mean using a confidence interval. If the sample standard deviation increases when all other factors remain the same, then the width of the confidence interval a) increases b) decreases c) stays the same
Assuming that the population is normally distributed, construct a 95% confidence interval for the population mean, based on the following sample size of n = 5. 1, 2, 3, 4, and 30 In the given data, replace the value 30 with 5 and recalculate the confidence interval. Using these results, describe the effect of an outlier (that is, an extreme value) on the confidence interval, in general. Find a 95% confidence interval for the population mean, using the formula or...
A random sample of 16 items is drawn from a population whose standard deviation is unknown. The sample mean is = 890 and the sample standard deviation is s= 15. Use Appendix D to find the values of Student's t. (a) Construct an interval estimate of u with 95% confidence. (Round your answers to 3 decimal places.) The 95% confidence interval is from O t o D (b) Construct an interval estimate of u with 95% confidence, assuming that s=...
A random sample of 175 items is drawn from a population whose standard deviation is known to be σ = 50. The sample mean is x¯x¯ = 920. (a) Construct an interval estimate for μ with 95 percent confidence. (Round your answers to 1 decimal place.) The 95% confidence interval is from to (b) Construct an interval estimate for μ with 95 percent confidence, assuming that σ = 100. (Round your answers to 1 decimal place.) The 95% confidence interval is...
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....
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...