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a. At 99% confidence, what is the margin of error?$b. Develop a 99% confidence interval estimate of the mean amount spent for lunch.$to $In the EAI sampling problem, the population mean is $51,100 and the population standard deviation is $5,000. When the sample size is n= 20, there is a 0.4108 probability of obtaining a sample mean within +/- $600 of the population mean.a. What is the probability that the sample mean is within $600 of the population mean if a sample of size 40 is used (to 4 decimals)?b. What is the probability that the sample mean is within $600 of the population mean if a sample of size 80 is used (to 4 decimals)?29.5037.503.5417.9825.060.55280.7154
{Exercise 8.41 (Algorithmic)}America's young people are heavy Internet users; 87% of Americans ages 12 to 17 are Internet users (The Cincinnati Enquirer, February 7, 2006). MySpace was voted the most popular website by 9% in a sample survey of Internet users in this age group. Suppose 1,150 youths participated in the survey. What is the margin of error, and what is the interval estimate of the population proportion for which MySpace is the most popular website? Use a 95% confidence level and round your answers to 3 decimals. For interval estimate Enter your answer using parentheses and a comma, in the form (n1,n2). Do not use commas in your numerical answer (i.e. use 1200 instead of 1,200, etc.)Margin error =Interval estimate =Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $20,000 and $40,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. How large a sample should be taken if the desired margin of error is:a. $500? Remove all commas from your answer before submitting.b. $230? Remove all commas from your answer before submitting.c. $90? Remove all commas from your answer before submitting.d. Would you recommend trying to obtain the $90 margin of error? Explain.A random sample of size 100 is selected from a population withp = .40.0.017(0.073,0.107)384181511856No, the sample size would probably be too time consuming and costly.
a. What is the expected value of p? (to 2 decimals) b. What is the standard error of p? (to 2 decimals)c. Show the sampling distribution of p. (to 2 decimals)= E(p) = d. What does the sampling distribution of p show?SOLUTIONThe 2003 Statistical Abstract of the United Statesreported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .30.a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02? Use 95% confidence. Remove all commas from your answer before submitting.b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers.