According to a recent report, the average American consumes 22.7 teaspoons of sugar each day (National Geographic Magazine, August 2013). Assuming that the distribution is approximately normal with a standard deviation of s 5 4.5, find each of the following values.

a. What proportion of people consume more than 30 teaspoons of sugar a day?

b. What proportion of people consume at least 20 teaspoons of sugar a day?