An insurance company handling malpractice cases is interested in estimating the average amount of claims against physicians of a certain specialty. The company plans to select a large sample and calculate the sample average X . Suppose the insurance company decides to use $6,000 as the standard deviation on the amount of claims. The company wishes to use X + 2000 as a 95% confidence interval to estimate the average amount. The minimum sample size required is closest to (a) 30 (b) 35 (c) 40 (d) 45 (e) 50