Answer :
Answer:
He needs a score of 28.7315 to qualify for the scholarship
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The mean score on the ACT is 21 with a standard deviation of 4.7
This means that [tex]\mu = 21, \sigma = 4.7[/tex]
What score does he need in order to qualify for the scholarship?
The top 5%, so the 100 - 5 = 95th percentile, which is X when Z has a p-value of 0.95, so X when Z = 1.645.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.645 = \frac{X - 21}{4.7}[/tex]
[tex]X - 21 = 4.7*1.645[/tex]
[tex]X = 28.7315[/tex]
He needs a score of 28.7315 to qualify for the scholarship