Students all over the United States recently took the National Science Foundation test on Biology. The mean score for girls was 150, with a standard deviation of 30. What is the…

Question

asked Jan 23, 2021 127k views

1 Answer

Eento · Answer 1 · 2021-01-29T06:45:45+0000

Answer:

z=(180-150)/(30)= 1

And if we find the probability using the normal standard distribution we got:

P(z<1)=0.841

And the the percentile would be approximately 84.1

Explanation:

For this case we define the random variable of interest as "Score for girls" and we know the following parameters:

$\mu =150, \sigma =30$

And we want to find the percentile for the score 180 and we can use the z score formula given by:

$z=(X -\mu)/(\sigma)$

And replacing we got:

z=(180-150)/(30)= 1

And if we find the probability using the normal standard distribution we got:

P(z<1)=0.841

And the the percentile would be approximately 84.1