The mean score on a college placement exam is 550 with a standard deviation of 150. If the scores vary normally, 90% of the test takers score above which score?
Question 3 options:
358 |
|
742 |
|
886 |
|
336 |
Solution: The correct option is 358
Explanation:
We are given:
We have to find the score above which lies 90% of scores. In other words, we have to find the score below which lies 10% of scores, Therefore, we first need to find the critical value corresponding to area = 0.10. Using the standard normal table, we have:
We can use the z -score formula. The formula is:
Therefore, 90% of the test takers above 358 score.
The mean score on a college placement exam is 550 with a standard deviation of 150....
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