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 stan- dard 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?

20. a recent report indicates that 2-year-old children from well-educated suburban families watched an average of m 5 60 minutes of television each day. assuming that the distribution of television-watching times is normal with a standard deviation of s 5 25 minutes, find each of the following
proportions.

a. what proportion of 2-year-old children watch more than 2 hours of television each day?
b. what proportion of 2-year-old children watch less than 30 minutes a day?

21. a report in 2010 indicates that americans between the ages of 8 and 18 spend an average of m 5 7.5 hours per day using some sort of electronic device such as smart phones, computers, or tablets. as- sume that the distribution of times is normal with a standard deviation of s 5 2.5 hours and find the following values.

a. what is the probability of selecting an individual who uses electronic devices more than 9 hours a day?

b. what proportion of 8- to 18-year-old americans spend between 8 and 12 hours per day using elec- tronic devices? in symbols, p (8 , x , 12) 5 ?

22. seattle, washington, averages m 5 34 inches of an- nual precipitation. assuming that the distribution of precipitation amounts is approximately normal with
a standard deviation of s 5 6.5 inches, determine whether each of the following represents a fairly typi- cal year, an extremely wet year, or an extremely dry year.

a. annual precipitation of 41.8 inches

b. annual precipitation of 49.6 inches

c. annual precipitation of 28.0 inches