According to the College Board website, the scores on the math part of the SAT (SAT-M) in a recent year had a mean of 507 and standard devia
Question
According to the College Board website, the scores on the math part of the SAT (SAT-M) in a recent year had a mean of 507 and standard deviation of 111. Assume that SAT-M scores have a normal probability distribution. One of the criteria for admission to a certain engineering school is an SAT-M score in the 98th percentile. This means the score is in the top 2% of scores. Find the actual SAT-M score marking the 98th percentile? Show your work. Interpret your result. Note: You will need the Inverse Normal Distribution Calculator below.
in progress
0
Math
3 months
2022-02-19T02:50:27+00:00
2022-02-19T02:50:27+00:00 1 Answer
0 views
0
Answers ( )
Answer:
The actual SAT-M score marking the 98th percentile is 735.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
[tex]\mu = 507, \sigma = 111[/tex]
Find the actual SAT-M score marking the 98th percentile
This is X when Z has a pvalue of 0.98. So it is X when Z = 2.054. So
[tex]Z = \frac{X – \mu}{\sigma}[/tex]
[tex]2.054 = \frac{X – 507}{111}[/tex]
[tex]X – 507 = 2.054*111[/tex]
[tex]X = 735[/tex]