## Question 804:

1## Answer:

No answer provided yet.To find the number of standard deviations a raw score is from the mean, we calculate a z-score. A z-score is the (data-point minus the mean)/ standard deviation. Z-scores can be both positive and negative and 0. A negative z-score means the raw score is below the mean and a positive z-score means the raw score is above the mean. A z-score of 0 means the raw score is exactly the mean.In this case we have a mean of 3.5 and want to know the number of standard deviations 1.5 is below the mean. Our equation is (1.5-3.5)/.5 = -2/.5 = 4.

So sally's score of 1.5 is 4 standard deviations below the mean. Another quick way to think about this to just see how many increments of .5 are between 1.5 and 3.5 and working backwards you see 3,2.5,2 and 1.5 also gets us 4.