When two measurements originate from different sources, converting them to the z scale helps to draw a sensible interpretation of their relative magnitudes. For instance, suppose a student scored 65 in a math course and 72 in a history course. These (raw) scores tell little about the student's performance. If the class averages and standard deviations were = 60, s = 20 in math and = 78, s = 10 in history, this student's

Thus, the student was .25 standard deviations above the average in math and .6 standard deviations below the average in history.
(a) If = 490 and s = 120, find the z scores of 350 and 620.
(b) For a z score of 2.4, what is the raw score if = 210 and s = 50?

Transcribed Image Text:

Measurement -x z-value of a measurement = 65-60-25 z score in math .25 = 20 7278 10 z score in history -60