The normal distribution The 68-95-99.7 Rule for Normal Distribu- tion: . About 68% (more precisely, 68.3%), or just over two-thirds, of the data points fall within 68% - Frequency (or relative frequency) 1 standard deviation of the mean. About 95% (more precisely, 95.4%) of the 95% data points fall within 2 standard deviations of the mean. 99.7% . About 99.7% of the data points fall within 3 -30 -20 -0 mean +0 +20 +30 standard deviations of the mean. (1) A survey finds that the prices paid for a two-year-old Ford Fusion cars are normally distributed with a mean of $10, 500 and a standard deviation of $500. Consider a sample of 20,000 people who bought two-year-old Ford Fusions. (a) How many people paid between $10, 000 and $11, 000? (b) How many people paid less than $10, 500? (c) How many people paid less than $10, 000? d) How many people paid more than $11, 500? (e) How many people paid between $10, 000 and $11, 500? (2) The mean weight of a quarter is 5.67 grams and the standard deviation is 0.07 grams. If vending machines are set to reject any quarters weighing more than 5.81 grams and less than 5.53 grams, what percentage of legal quarters will be rejected by the vending machine