Drivers pay an average of (mean $690) per year for automobile insurance the distribution of insurance payments is approximately normal with a standard deviation of 110 dollars. What proportion of drivers pay more than 100 dollars per year for insurance?

Answer 1

Use z-scores.

z = (x - mean)/sd

x = 100
mean = 690
sd = 110

Plug the values into the formula, then use a z-table to determine the proportion.

I hope this will help get you started.