The Wall Street Journal reported that automobile crashes cost the US $162 billion annually. The average cost per person for crashes in the Tampa, FL area was reported to be $1599. Suppose this average cost was based on a sample of 50 persons who had been involved in car crashes and that the population standard deviation is o=$600. What is the margin of error for a 95% confidence interval? What would you recommend if the study required a margin of error of $150 or less?