please help.

A large study of the heights of 540 adult men found that the mean height was 69 inches tall. The standard deviation was 6 inches. If the distribution of data was normal, what is the probability that a randomly selected male from the study was between 57 and 75 inches tall? Use the 68-95-99.7 rule.

Answer = (Write your answer in decimal form, not percentage form. For example, if your percentage is 99%, enter 0.99, not 99. Round your answer to three decimal places.)