Since

is 2 standard deviations above the mean, you're looking for the probability that

The empirical rule says that approximately 95% of a normal distribution lies within 2 standard deviations of the mean, or

.
Since the normal distribution is symmetric, you have
So -12y+30+6y+18 because you multiply the number on the outside of the parentheses by both numbers inside, then you collect like terms so -6y+48
25miles/hour
1 mile=5280 feet
25*5280ft/hour
132,000ft/hour
Hope this helps!