A brisk walk at 4 miles per hour burns an average of 320 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

More than 309 calories The probability that a randomly selected person burns more than 309 calories is _%