chapter 1

Chapter 1: Overview and Descriptive Statisticsb.Interval Frequency Rel. Freq. Density0 -< 2 23 .500 .2502 -< 4 9 .196 .0984 -< 6 7 .152 .0766 -< 10 4 .087 .02210 -< 20 1 .022 .00220 -< 30 2 .043 .0040.250.20Density0.150.100.050.00024610Repair Time203078.a. Since the constant x is subtracted from each x value to obtain each y value, andaddition or subtraction of a constant doesn’t affect variability,s = and sy= sx2 2ys xb. Let c = 1/s, where s is the sample standard deviation of the x’s and also (by a ) of the y’s.Then s z = cs y = (1/s)s = 1, and s z 2 = 1. That is, the “standardized” quantities z 1 , … , z nhave a sample variance and standard deviation of 1.42