chapter 1

Chapter 1: Overview and Descriptive Statistics56. A boxplot (created in Minitab) of this data appears below.0100200300aluminum400500There is a slight positive skew to this data. There is one extreme outler (x=511). Even whenremoving the outlier, the variation is still moderately large.57.a. 1.5(IQR) = 1.5(216.8-196.0) = 31.2 and 3(IQR) = 3(216.8-196.0) = 62.4.Mild outliers: observations below 196-31.2 = 164.6 or above 216.8+31.2 = 248.Extreme outliers: observations below 196-62.4 = 133.6 or above 216.8+62.4 = 279.2. Ofthe observations given, 125.8 is an extreme outlier and 250.2 is a mild outlier.b. A boxplot of this data appears below. There is a bit of positive skew to the data but,except for the two outliers identified in part (a), the variation in the data is relativelysmall.* *120 140 160 180 200 220 240 260x58. The most noticeable feature of the comparative boxplots is that machine 2’s sample valueshave considerably more variation than does machine 1’s sample values. However, a typicalvalue, as measured by the median, seems to be about the same for the two machines. Theonly outlier that exists is from machine 1.28