70 confidence interval for the mean price charged by discount brokers for a trade of 100 shares at $50 per share. 45. A survey conducted by the American Automobile Association showed that a family of four us aspends an average of $215.60 per day while on vacation. Suppose a sample of 64 families of four vacationing at Niagara Falls resulted in a sample mean of $252.45 per day and a twoin sample standard deviation of $74.50. If al cbinga. Develop a 95% confidence interval estimate of the mean amount spent per day by a family of four visiting Niagara Falls. Hing ab. Based on the confidence interval from part (a), does it appear that the population mean amount spent per day by families visiting Niagara Falls differs from the mean reported Dean ad mao by the American Automobile Association? Explain