Question

The scores on a psychology exam were normally distributed with a mean of 61 and a standard deviation of 5. A failing grade on the exam was anything 2 or more standard deviations below the mean. What was the cutoff for a failing score? Approximately what percentage of the students failed ?

Answer 1

The cutoff for a failing score is 51 and about 2.28% of the students failed the psychology exams.

What is an equation?

An equation is an expression that shows the relationship between two or more numbers and variables.

Z score is given by the equation:

z = (raw score - mean) / standard deviation

Given mean of 61 and a standard deviation of 5.

The z score that corresponds to 2 or more standard deviations below the mean is -2. Hence:

-2 = (x - 61) / 5

x = 51

P(z < -2) = 0.0228

The cutoff for a failing score is 51 and about 2.28% of the students failed the psychology exams.

Find out more on equation at: brainly.com/question/2972832

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