In a study of government financial aid for college students, it becomes necessary to estimate the percentage of full-time college students who earn a bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.01 margin of error and use a confidence level of 90%. Complete parts (a) through (c) below. a. Assume that nothing is known about the percentage to be estimated. (Round up to the nearest integer.) b. Assume prior studies have shown that about 60% of full-time students earn bachelor's degrees in four years or less. n=D (Round up to the nearest integer.) c. Does the added knowledge in part (b) have much of an effect on the sample size? O A. No, using the additional survey information from part (b) only slightly reduces the sample size. O B. No, using the additional survey information from part (b) does not change the sample size. OC. Yes, using the additional survey information from part (b) only slightly increases the sample size.

You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals. A random sample of 50 home theater systems has a mean price of $119.00. Assume the population standard deviation is $19.80. .... Construct a 90% confidence interval for the population mean. The 90% confidence interval is ( ). (Round to two decimal places as needed.) Construct a 95% confidence interval for the population mean. The 95% confidence interval is (J. ). (Round to two decimal places as needed.) Interpret the results. Choose the correct answer below. O A. With 90% confidence, it can be said that the population mean price lies in the first interval. With 95% confidence, it can be said that the population mean price lies in the second interval. The 95% confidence interval is…

Find the sample size needed to estimate the percentage of adults who can wiggle their ears. Use a margin of error of 5 percentage points and use a confidence level of 90%. Complete parts (a) and (b) below. a. Assume that p and q are unknown. n = (Round up to the nearest integer.)

I only need part B

Answer Part B

Use the sample data and confidence level given below to complete parts (a) through (d). A research institute poll asked respondents if they felt vulnerable to identity theft. In the poll, n= 1004 and x = 575 who said "yes." Use a 90% confidence level. E Click the icon to view a table of z scores. .... a) Find the best point estimate of the population proportion p. (Round to three decimal places as needed.)

Researchers studied the mean egg length (in millimeters) for a bird population. After taking a random sample of eggs, they obtained a 95% confidence interval of (45,60). What is the value of the margin of error? Choose the correct answer below. A. 15 mm B. 52.5 mm O c. 7.5 mm O D. 1.96

If the analyst decides to increase the sample size (n) from 75 to 100, while maintaining the same confidence level, the width of the confidence interval would then: fluctuate up and down. remain unchanged. decrease. increase.

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and Questions Navigation Menu inary estimate of the proportion who smoke of .26 a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02 (to the nearest whole number)? Use 95% confidence. b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population (to 4 decimals)? c. What is the 95% confidence interval for the proportion of smokers in the population (to 4 decimals)?