B?

20 21 22 23 24 25 26 27 28 A brisk walk at 4 miles per hour burns an average of 310 calories per hour. If the standard deviation of the distribution is 7 calories, find the probability that a person who walks 1 hour at the rate of 4 miles per hour will burn the given number of calories. Assume the random variable is normally distributed. Refer to the table of values (@ Area Under the Standard Normal Distribution) as needed. If necessary, round intermediate calculations to the nearest hundredth. Part 1 of 3 (a) More than 274 calories The probability that a randomly selected person burns more than 274 calories is 100 %. Part: 1 / 3 Part 2 of 3 (b) Less than 284 calories The probability that a randomly selected person burns less than 284 calories is % X