rOr or the possibility that a particular random sample may not be a good repre-entation of the population. In each of these four samples, the mean of the sampleeither much less or much more than the population mean. Because of randomsampling, the mean of the sample is not a good estimate of the population mean,nd the confidence Interval based on the sample's mean does not include the pop-ulation mean.ELF-REVIEW 9-1The Bun-and-Run is a franchise fast-food restaurant located in the Northeast specializing inhalf-pound hamburgers, fish sandwiches, and chicken sandwiches. Soft drinks and Frenches also are available. The Marketing Department of Bun-and-Run Inc. reports that thedistributlon of daily sales for their restaurants follows the normal distribution and that thepopulation standard deviation Is $3,000. A sample of 40 franchises showed the mean dailysales to be $20,000.(a) What is the population mean of dally sales for Bun-and-Run franchises?(b) What Is the best estimate of the population mean? What is this value called?ic) Develop a 95% confidence interval for the popuiation mean of daily sales.(d) Interpret the confidence interval,EXERCISES1.A sample of 49 observations Is taken from a normal population with a standarddeviation of 10. The sample mean is 55. Determine the 99 % confidence Interval forthe population mean.2. A sample of 81 observations Is taken from a normal population with a standarddeviation of 5. The sample mean Is 40. Determine the 95% confidence Interval forthe population mean. bnal3. A sample of 250 observations Is selected from a normal population with a popula-tlon standard devlation of 25. The sample mean Is 20.a. Determine the standard error of the mean.b. Explain why we can use formula (9-1) to determlne the 95% confidence interval.c. Determine the 95% confidence Interval for the population mean.4. Suppose you know a and you want an 85% confidence level. What value would youuse as z in formula (9-1)75. A research firm conducted a survey to determine the mean amount Americansspend on coffee during a week. They found the distribution of weekly spendingfollowed the normal distributlon with a population standard devlation of $5. A sam-pie of 49 Americans revealed that $20.a. What is the point estimate of the population mean? Explain what It Indicates.b. Using the 95% level of confidence, determine the confidence Interval for p. Ex-plain what it indicates.6. Refer to the prevlous exercise. Instead of 49, suppose that 64 Americans were sur-veyed about their weekly expenditures on coffee. Assume the sample mean re-mained the same.a. What is the 95% confidence Interval estimate of u?h. Explaln why this confidence Interval is narrower than the one determined In theprevlous exercise.7. Bob Nale is the owner of Nale's Quick Fill. Bob would lke to estimate the meennumber of gallons of gasollne sold to his customers. Assume the number of gallonssold follows the normal distributlon with a population standard devlation of 2.30gallons. From his records, he selects a random sample of 60 sales and finds themean number of gallons sold Is 8.60.a. What is the polnt estimate of the population mean?b. Develop a 99% confidence Interval for the population mean.c. Interpret the meaning of part (b).CHE

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Here as PER POLICY I HAVE CALCULATED CALCULATED MAIN QUESTION 9.1