A mandatory competency test for high school sophomores has a normal distribution with a mean of 553 and a standard deviation of 90. The top 3% of students receive a $500 prize. What is the minimum (cutoff) score you would need to receive this award?

Respuesta :

Answer:

The minimum (cut off) score you need to receive this award is;

[tex]722.2[/tex]

Explanation:

Given that the top 3% of the students receive a $500 prize.

[tex]P=1-0.03=0.97[/tex]

We will then find the z-score that corresponds to the given probability.

[tex]z=1.88[/tex]

Recall that;

[tex]z=\frac{X-\mu}{\sigma}[/tex]

Given;

[tex]\begin{gathered} \mu=553 \\ \sigma=90 \end{gathered}[/tex]

substituting the values;

[tex]\begin{gathered} 1.88=\frac{X-553}{90} \\ X-553=1.88\times90 \\ X=553+1.88\times90 \\ X=722.2 \end{gathered}[/tex]

Therefore, the minimum (cut off) score you need to receive this award is;

[tex]722.2[/tex]