Answer
P(X > 34) = 0.0052. This implies that if we take 1000 samples of size 20, about 5 will have a mean mpg of 34 miles per gallon or more.
Work Step by Step
Here we have n = 10
$σ_{x̅} = \frac{σ}{n} = \frac{3.5 }{\sqrt 20} = 0.78$
$z = \frac{x̅ - μ_{x̅}}{σ_{x̅}} = \frac{34-32}{0.78} = 2.56$
P(X > 34) = P(z > 2.56) = 0.0052
