Consider a normal distribution of IQ scores which have a mean of 100 and a standard deviation (SDs) of 15. How many SDs below the mean is someone with an IQ of 70?

Question

Quizplus · Accepted Answer

To find how many SDs below the mean a score of 70 is, we need to use the formula: (observed value - mean) / SD. Plugging in the values, we get (70-100) / 15 = -2. Therefore, someone with an IQ of 70 is 2 SDs below the mean. The answer is C.

Consider a Normal Distribution of IQ Scores Which Have a Mean