He coud walk 5 meters in one hour because i did 60-12-12-12-12 and then you have a extra 12 so he got 5 meters in one hour part b he can 1 more further because 1 meter because before it was 12 hope explained it right
The empirical rule you're referring to is the 68-95-99.7 rule, which asserts that for a normal (bell-shaped) distribution, approximately 68% of the distribution lies within 1 standard deviation of the mean; 95% lies within 2 standard deviations of the mean; and 99.7% lies within 3 standard deviations of the mean.
Let be the random variable denoting vehicle speeds along this highway. We want to find . To use the rule, we need to rephrase this probability in terms of the mean and standard deviation.
Notice that , and . In other words, 61 and 79 both lie exactly 3 standard deviations away from the mean, so .