ABSTRACT
This chapter discusses the fundamentals of numbers, probability distributions, standard scores, and statistical ways to check measurement techniques. All numbers are not created equal. Ratio numbers are numbers that can be divided into each other to form meaningful ratios. This is the type of number that carries the most information. The standard deviation turns out to be a very important number because the variability of a distribution determines how "valuable" each unit is—that is, how significant it is for two scores to be one measurement unit apart. Similar to percentile rank is a measurement called, simply, "percentile." The percentile is a particular score, on an ordered list of scores, at or below which a given percent of the other scores fall. In power lifting, the measurement units don't appear to be different, but in fact they are. Pounds lifted do not always equal pounds lifted, and, therefore, some pounds can't necessarily be added to or subtracted from other pounds.
