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6. What are the odds of scoring 60% or better on a 20 question

True and False test simply by guessing?

User Ryland
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1 Answer

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The odds of scoring 60% or higher are 0.25 or 25.17%.


Each True/False question has 2 options.
12/20 = 0.6 or 60%
So you’d need to get at least 12 correct for a score of 60%.
The probability of getting 1 question correct is 1/2, and this is true of each question on the test.
In the formula, N = total number of items in the test; x = number of choices per item; C = number of correct responses. You want to find P(x >= 12), which is to score 60 percent or higher. The probability of getting 12 or more questions on the test correct.

The probability of getting 12 or more correct out of 20 questions by chance with 2 choices per item = 25.1722%.
User Suat
by
7.7k points
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