The weight of a soccer ball is normally distributed with a mean of 21 oz and a standard deviation of 3 oz. Suppose 1000 different soccer balls are in a warehouse. About how many soccer balls weigh more than 24 ozA. 40B. 80 C. 160 D. 200

Accepted Solution

A weight of 24 oz is 1 standard deviation above the mean 21 oz. The empirical rule says approximately 68% of soccer balls have weights within 1 standard deviation (i.e. between 18 and 24 oz), so the remaining 32% of balls have weights below 18 oz or above 24 oz. The balls' weights are normally distributed, so the percentage of balls with weight less than 18 oz is the same as the percentages of balls with weight greater than 24 oz, which means about 16% of balls have weight greater than 24 oz. 16% of 1000 is 160.