DS. At a golf driving range, a computer automatically records the length of each drive. The distribution of drive lengths follow a normal distribution, Is the percentage of drives over 200 feet in length greater than15%. 1. The average drive length is 150 feet 2.The standard deviation is 50 the answer is c princeton gives explanation : The question states that the drive lengths follow a normal distribution, which means that tatio of items within 1,2,and 3 standard deviation from the mean is 34:14:2. Taken together, statements 1. and 2. provide the mean and the standard deviation, so we can calculate what percent of drives are over 200 feet in length. If the mean is 150 and the standard deviation is 50, then 34% of the deviation between 150 and 200feet, 14% are between 200and 250, and 2% are between 250 and 300. Thus 16% of the drives are over 200 feet in length. 这道题我看不懂，只好求教大家了． | 
