Soc 2205 chapter 4: the normal curve. Raw ) scores and z scores are two equally valid but different ways of measuring distances under the curve: amal"s iq score was 120 or amal scored one standard deviation above the mean. Finding z scores: subtract the value of the mean from the value of the score the quantity found in step 1 by the value of the standard deviation (s). The result is the z- score equivalent for this raw score. 4. 3 the normal curve table: the normal curve a detailed description of the area between a z score and the mean of a standardized normal distribution. An illustration of how to find areas under the normal curve using appendix a (a) z (b) area between. The entry column b is 0. 3413. we can easily translate these into percentages by multiplying them by 100: a proportion of 0. 3413 of the total area under the curve lies between a z score of.