You may need to use the appropriate appendix table or technology to answer this question. A simple random sample of 40 items resulted in a sample mean of 25. The population standard deviation is a = 5. (Round your answers to two decimal places.) (a) What is the standard error of the mean, 0;? (b) At 95% confidence, what is the margin of error? E You may need to use the appropriate appendix table or technology to answer this question. Studies show that massage therapy has a variety of health benefits and it is not too expensive. A sample of 13 typical one-hour massage therapy sessions showed an average charge of $55. The population standard deviation for a one-hour session is a = $6.5. (a) What assumptions about the population should we be willing to make if a margin of error is desired? O We should be willing to make the assumption that the population is approximately normal. 0 We should be willing to make the assumption that the population is approximately bimodal. 0 We should be willing to make the assumption that the population is approximately skewed right. 0 We should be willing to make the assumption that the population is approximately skewed left. 0 We should be willing to make the assumption that the population is approximately uniform. (b) Using 95% condence, what is the margin of error in dollars? (Round your answer to the nearest cent.) $: (c) Using 99% condence, what is the margin of error in dollars? (Round your answer to the nearest cent.) $: You may need to use the appropriate appendix table or technology to answer this question. A simple random sample of 60 test scores resulted in a sample mean of 80. The population standard deviation is a = 10. (a) Compute the 95% confidence interval for the population mean. (Round your answers to two decimal places.) [:1 to [:1 (b) Assume that the same sample mean was obtained from a sample of 120 test scores. Provide a 95% condence interval for the population mean. (Round your answers to two decimal places.) :1\"): (c) What is the effect of a larger sample size on the interval estimate? 0 A larger sample size provides a larger margin of error. 0 A larger sample size does not change the margin of error. 0 A larger sample size provides a smaller margin of error. You may need to use the appropriate appendix table or technology to answer this question. The following sample data for the weight of two homemade chocolate chip cookies (in ounces) are from a normal population: 13, 11, 15, 18, 16, 14, 9, 8. (a) What is the point estimate of the population mean? :l (b) What is the point estimate of the population standard deviation? (Round your answer to three decimal places.) :l (c) With 95% confidence, what is the margin of error for the estimation of the population mean? (Round your answer to one decimal place.) :l (d) What is the 95% condence interval for the population mean? (Round your answer to one decimal place.) :lto: (e) Which are correct interpretations of the 95% confidence interval for the population mean, in the context of the problem? (Select all that apply.) We are 95% condent that the true mean weight of two homemade chocolate chip cookies is between the values listed in part (d). There is a 0.95 probability that the true mean weight of two homemade chocolate chip cookies is between the values listed in part (d). I: I: I: We are 95% condent that the mean weight of the sample of eight sets of two homemade chocolate chip cookies is between the values listed in part (d). I: If 100 samples of eight sets of cookies are taken, and a 95% confidence interval is determined for the true average weight using each set of sample data, about 95 of the 100 condence intervals will contain the true mean weight of two homemade chocolate chip cookies