You may need to use the appropriate appendix table or technology to answer this question. The 92 million Americans of age 50 and over control 50 percent of all discretionary income. AARP estimates that the average annual expenditure on restaurants and carryout food was $1,873 for individuals in this age group. Suppose this estimate is based on a sample of 70 persons and that the sample standard deviation is $850. (a) At 95% confidence, what is the margin of error in dollars? (Round your answer to the nearest dollar.)