Question

A car is designed to last an average of 12 years with a standard deviation of 0.8 years.

What is the probability that a car will last less than 10 years?

Answer 1

calculate the z-score that corresponds to 10 years

z-score = (x - μ) / σ
in this case, x = 10 years, μ = mean = 12 years, σ = standard dev. = 0.8 years

once you have your z-score, use a z-table/calculator to find the corresponding probability value