Answer
0.2266
Work Step by Step
Here, we have μ = 445 , $σ_{x̅} = 6.695$ (from part 19.20)
Using the z-value approach:
$z = \frac{x̅ - μ_{x̅}}{σ_{x̅}} = \frac{450-445}{6.695} = 0.7468$
Using Table A of the book:
P(z > 0.7468) = 0.2266