3) According to the American Time Use Survey results released by the Bureau

of Labor Statistics on June 24, 2015, Americans aged 15 and over watched television for an average of 168 minutes per day. Suppose that the current distribution of times spent watching television per day by all Americans age 15 and over has a mean of 168 minutes and a standard deviation of 20 minutes. Find the probability that the average time spent per day watching television by a random sample of 400 Americans age 15 and over is:

Round to 3 decimals.

(a)165.70 to 167 minutes

(b)more than 169.8 minutes

(c)at most 163 minutes