The ACT score was better since the z-score of the ACT is greater than the z-score of the SAT. Then the correct option is B.
What is a normal distribution?
It is also called the Gaussian Distribution. It is the most important continuous probability distribution. The curve looks like a bell, so it is also called a bell curve.
The z-score is a numerical measurement used in statistics of the value's relationship to the mean of a group of values, measured in terms of standards from the mean.
The z-score is given as
[tex]\rm z = \dfrac{x - \mu }{\sigma}[/tex]
In 1985, the average ACT score was 18 with a standard deviation of 6.
Also in 1985, the average SAT score was 500 with a standard deviation of 100.
Dr. Robertson took both tests in 1985 and scored a 26 on the ACT and a 620 on the SAT.
Then the z-score of the ACT will be
[tex]\rm z = \dfrac{26 - 18}{6}\\\\z = 1.3333[/tex]
Then the z-score of the SAT will be
[tex]\rm z = \dfrac{620 - 500}{100}\\\\z = 1.2[/tex]
Then the ACT score was better since the z-score of the ACT is greater than the z-score of the SAT.
More about the normal distribution link is given below.
https://brainly.com/question/12421652
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