The percentage of boys 16- to 17-years-old who wear a size 11 shoe or larger is 3.59%.
<u>Step-by-step explanation:</u>
Step 1: Sketch the curve.
The probability that X>27.9 is equal to the blue area under the curve.
Step 2:
Since μ=25.2 and σ=1.5 we have:
P ( X > 27.9 ) = P ( X−μ > 27.9−25.2 )
⇒ P ( X−μ/σ > 27.9−25.2/1.5)
Since Z=x−μσ and 27.9−25.21.5=1.8 we have:
P ( X>27.9 )=P ( Z>1.8 )
Step 3: Use the standard normal table to conclude that:
P (Z>1.8)=0.0359
Percentage = %
Therefore , The percentage of boys 16- to 17-years-old who wear a size 11 shoe or larger is 3.59%.
