Concept explainers
Determining
31. Lefties Find the sample size needed to estimate the percentage of California residents who are left-handed. Use a margin of error of three percentage points, and use a confidence level of 99%.
a. Assume that
b. Assume that based on prior studies, about 10% of Californians are left-handed.
c. How do the results from parts (a) and (b) change if the entire United States is used instead of California?
Learn your wayIncludes step-by-step video
Chapter 7 Solutions
ELEMENTARY STATISTICS-W/ACCESS >CUSTOM<
Additional Math Textbook Solutions
Introductory Statistics (10th Edition)
Statistics: The Art and Science of Learning from Data (4th Edition)
Basic Business Statistics, Student Value Edition (13th Edition)
Introductory Statistics (2nd Edition)
Elementary Statistics: Picturing the World (6th Edition)
- Determine the point estimate of the population mean and margin of error for the confidence interval. Lower bound is 20,upper bound is 24. The point estimate of the population mean isarrow_forwardFind the minimum sample size required to estimate the proportion of the population that supports a political candidate if the required margin of error is 0.042 and the level of confidence is 90%arrow_forwardHow Much Alcohol Do College Students Drink? According to the website www.collegedrinkingprevention.gov, “About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall.” A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 71 students. The sample mean is 3.93 alcoholic drinks per week. The sample standard deviation is 3.78 drinks. Here is an applet you can use when directed to find the critical T-value.Note: the "Central Probability" is the area of the middle shaded region. 1. Find the critical T-value for this 90% confidence interval. Hint: Use the applet to find the T-value for 90% confidence with df = 71 – 1 = 70.arrow_forward
- How do I find the minimum sample size with a 99 percent confidence level?arrow_forwardconstructu a 95% confidence interval estimate for the population standard deviation, of the annual salaries of software engineers if a sample of 14 randomly selected software engineers has a standard deviation of $3725. (a) Determine X^2L and X^2R. (b) write down the formula and the calculate the confidence interval. follow the proper rounding rulesarrow_forwardThe Ministry of Health in the Canadian province of Ontario wants to know whether the national health care system is achieving its goals in the province. Much information about health care comes from patient records, but that source does not allow to compare people who use health services with those who do not. So the Ministry of Health conducted the Ontario Health Survey, which interviewed a random sample of 61239 people who live in the province of Ontario. Estimate the margin of error for conclusions having 95% confidence about the entire adult population of Ontario. Give your answer to three decimal places.arrow_forward
- Construct a confidence interval for a population mean. In order to estimate the number of 911 calls at the emergency operations center (EOC) in Pineville, volunteers randomly contacted 40 similar EOCs around the nation. They learned that the Mean is 42.0 calls per month and that the Standard Dev is 6.5 calls per month. Construct a 95% confidence interval of the mean calls at the EOCs per month.arrow_forwardHow tp use a sample mean to calculate a confidence interval?arrow_forwardIs there a significant difference between the sample mean of scores and the population mean? Carry out all 9 steps of the hypothesis testing. Use =0.05arrow_forward
- The mean and standard deviation of the blood sugar level of randomly selected 50 patients in a hospital are 130mg/dl and 4.6 mg/dl, respectively. a. Determine the point estimate of the population mean. b. What is the margin of error? c. Find the 90% confidence interval for the mean of all patients in the hospital.arrow_forwardA sociologist wishes to conduct a poll to estimate the percentage of Americans who favor affirmative action programs for women and minorities for admission to college and universities. She wants to use a 2003 estimate of 55% obtained from a Gallup Youth Survey as a prior estimate. What sample size should be obtained if she wishes the estimate to be within 4 percentage points with 90% confidence?arrow_forward2) Using StatCrunch* and the available data, construct a 99% Confidence Interval for the proportion of all patients experiencing High CoVID-19 severity if they are a Never Smoker. a. Report the confidence interval using proper notation. b. In one to two complete sentences, state an interpretation for this confidence interval.arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman