Answer
$0.0116=1.16$%
Work Step by Step
Let's find the z-score for 60,000 miles:
$z=\frac{X-μ}{σ}=\frac{60000-70000}{4400}=-2.27$
According to Table V, the area to the left (tires will last 60,000 miles or less) of the standard normal curve for a z-score equal to -2.27 is 0.0116.
