Find the z-scores that bound the middle 74% of the area under the standard normal curve.

Since 74% of the middle area is bounded, this means that there is 13% on the left side, and another 13% on the right side.

P (left) = 0.13

P (right ) = 1 - 0.13 = 0.87

At this P values, the z scores are approximately:

z score (left) = -2.22

z score (right) = 1.13

a 10 percent increase

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,