Solution :
Given :
National mean score of the reading test that is conducted the NAEP = 288
Standard deviation of the score = 38
Therefore, P(X > x) = 0.25
P (Z > [tex]$\frac{x-288}{38} $[/tex] = 0.674)
[tex]$\frac{x-288}{38} = 0.674$[/tex]
[tex]$x=288+(38 \times 0.674)$[/tex]
x = 326.67
Therefore, the highest score that is needed for the students to be in the top of 25 percent among the students those who take the exam.
