The scores on a standardized test are normally distributed with a mean of 100 and standard deviation of 10. What test score is 2.2 standard deviations below the mean?
To find the test score that is 2.2 standard deviations below the mean, we can use the formula:
Test score = Mean - (Standard deviation) * (Number of standard deviations)
Plugging in the values:
Test score = 100 - (10) * (2.2)
Calculating:
Test score = 100 - 22
Test score = 78
Therefore, the test score that is 2.2 standard deviations below the mean is 78.