Quiz: Module 5: Univariate Confidence Intervals - Quiz Time Limit: 01:40:00 Submi An admissions director wants to estimate the mean age of all students enrolled at a college. The est hin 1.1 years of the population mean. Assume the (a) Determine the minimum sample size required to construct a 90% confid n standard deviation is This Question: 1 pt 12 of 12 (0 complete) This Quiz: 12 pts possible years. (b) The sample mean is 20 years of age. Using the minimum sample size with a 90% level of confidence, does it seem likely that the population mean could be within In a survey of 2266 adults, 736 say they believe in UFOs. Click here to view page 1 of the Standard Normal Table. Click here to view page 2 of the Standard Normal Table Construct a 99% co or the population proportion of adults who behave in UFOS. (a) The minimum sample size required to construct a 90% confidence interval is students. (Round up to the nearest whole number.) A 99% confidence interval for the population proportion is (). (Round to three decimal places as needed.) (b) The 90% confidence interval is (). it | |seem likely that the population mean could the sample mean because 8% off from the Interpret y ct answer below. sample mean would fall the confidence interval. It seem likely that the population mean could be within 9% of the sample mean because 9% off from the sample mean would fall the confidence interval. A. With 99% confidence, it can be said that the population proportion of adults who believe in UFOs is between the endpoints of the given confidence interval. (Round to two decimal places as needed.) O B. The endpoints of the given confidence interval shows that 99% of adults believe in UFOs. O c. With 99% confidence, it can be said that the sample proportion of adults who believe in UFOs is between the endpoints of the given confidence interval. O D. With 99% probability, the population proporti he endpoints of the given confidence interval. Find the critical value zo that corresponds to a 95% confidence level. Find the margin of error for the given values of c, s, and n. O A. + 1.645 c = 0.98, s = 6, n= 23 O B. +2.575 OC. + 1.96 Click the icon to view the t-distribution table. OD. +2.33 The margin of error is . (Round to one decimal place as needed.) uiz. Module S. Univariate Confidence Intervals - Quiz Time Limit: 01:40 his Question: 1 pt his Question: 1 pt 10 of 12 (0 complete ) JH This Quiz: 12 Use the standard normal distribution or the t-distribution to construct a 90% confidence interval for the population mean. Justify your decision. If neither distribution can be used , explain why. Interpret the results . Determine the point estimate of the population mean and margin of error for the confidence interval with lower bound of 20 and upper bound of 28. In a random sample of 13 mortgage institutions, the mean interest rate was 3.52% and the standard deviation was 0.32%. Assume the interest rates are normally O A. X= 28, E=4 distributed . OB. X= 24, E = 4 Which distribution should be used to construct the confidence interval? O C. X = 24 , E = 8 O A. Use a t-distribution because re normally distributed and o is known. O D. X= 20, E = 8 O B. Use a normal distribution because the interest rates are normally distributed and o is known. O c. Use a t-distribution because it is a random sample, o is unknown, and the interest rates are normally distributed O D. Use a normal distribution because n
