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SAT versus ACT Eleanor scores 680 on the SAT Mathematics test. The distribution of SAT scores is

symmetric and single-peaked, with mean 500and standard deviation 100. Gerald takes the American College Testing (ACT) Mathematics test and scores 27. ACT scores also follow a symmetric, singlepeaked distribution鈥攂ut with mean 18 and standard deviation 6. Find the standardized scores for both students. Assuming that both tests measure the same kind of ability, who has the higher score?

Short Answer

Expert verified

The standardized score for E is 150 and the standardized score for G is 180

Step by step solution

01

Step 1. Given

The average score on the SAT Mathematics test is 500. Eleanor received a 680 on the SAT Mathematics test. The SAT Mathematics test has a standard deviation of 100. Gerald received a 27on the ACT Mathematics test. The average ACT Mathematics test score is 18 points. The ACT Mathematics exam score has a standard deviation of 6 points.

02

Step 2. Concept

The inflection points are the points where the curve shifts from being concave up to being concave down. These inflection points are always one standard deviation distant from the mean on a normal density curve.

03

Step 3. Explanation

Eis's standardized score is shown below.

z(Eleanor)=x=680500100=1.80

The standardized score for G can be found in the table below.

z(Gerald)=x=27186=1.50

E's score of 680was 1.80standard deviations higher than the mean, whereas G's score of27was 1.50standard deviations higher. Therefore, the standardized score for Eis 180 and the standardized score for G is 150

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