Answer:
Option D)
The area below the standardized test score is 0.8413
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 85
Standard Deviation, σ = 5
We are given that the distribution of score is a bell shaped distribution that is a normal distribution.
Formula:
[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]
P(score is below 90)
[tex]P( x < 90) = P( z < \displaystyle\frac{90 - 85}{5}) = P(z < 1)[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(x < 90) =0.8413 = 84.13\%[/tex]
Thus, the correct answer is
Option D)
The area below the standardized test score is 0.8413
