I need help on A and B A survey was conducted to estimate the population mean number of hours adult Americans spend working per week. A 95% confidence interval was constructed:a 95% confidence interval for μ: (40.1, 43.9) hours per week.A. What is a point estimate of the population mean number of hours adult Americans work per week?hours (do not round)Answer:B. What was the margin of error in this study?Answer =hours (do not round)C. Which of the following would be a suitable interpretation of the interval?We are 95% confident that the sample mean number of hours adult Americans spend working per week is between 40.1 and 43.9 hours.We are 95% confident that the population mean number of hours adu NSAIDs (1).docx pend working per week is between 40.1 and 43.9 hours.We are 95% confident that an adult American spends between 40.1 and 43.9 hours working per week.95% of all adult Americans spend between 40.1 and 43.9 hours working per week.D. If the researchers wanted to reduce the margin of error in the study, what could they do?Increase the sample size or Decrease the confidence level.

The 95% confidence interval estimate for the population mean number of hours adult Americans spend working per week μ is 40.1 , 43.9 .A. The point estimate of the population mean is the sample mean. Consider x¯ as the sample mean and E as the margin of error at 95% confidence. Therefore, 95% confidence interval for population mean μ is C.I.=x¯-E , x¯+E Hence, it can be written that, x¯-E=40.1x¯+E=43.9 Adding the above 2 equations, 2x¯=40.1+43.9=84x¯=842=42 Therefore the point estimate of the population mean number of hours adult Americans spend working per week is 42 hours.B. Substituting x¯=42 in the equation x¯-E=40.1 and solving for E , we get the margin of error as 42-E=40.1E=42-40.1=1.9 The margin of error i this study is 1.9 hours.