3.4

5 -.30, -.43; so relative to the gestation period, the 40-week baby weighs less

7 The man is relatively taller.

9 Clayton Kershaw’s ERA = 2.30 standard deviations below the National League. Hernandez’s ERA = 1.91 standard deviations below the American League’s mean ERA. So, Kershaw had the better year.

11 Ryan = 3.39 standard deviations below the mean in the 100 m back, 3.05 standard deviations below the mean in the 200 m back. This shows that Ryan is better at the 100 m race.

13 239

15

  1. 15% of 3-5 month old males have a circumference that is 41 cm or less. 85% of 3-5 month old males have a circumference that is more than 41.0 cm

  2. 90% of 2-year old females have a waist circumference that is 52.7 cm or less. 10% of 2-yr old females have a waist circumerference that is more than 52.7 cm.

  3. The heights at each percentile decrease as the age increases, which shows that adult males are getting taller.

22

  1. (hint the mean = 10.08, standard deviation = 1.885), -1.21

  2. Q1 = 8.9, Q2 = 9.95, Q3 = 11

  3. 2.1

  4. Upper fence = 12.5, Lower fence = -.45. Outliers = 12.9, 13, 13.4

25 By hand, the cut off point is 574 minutes. The cusomter is contacted if more minutes are used.

3.5

3

  1. Skewed right

  2. 0,1,3,6,16

4

  1. Symmetric

  2. -1, 2 , 5, 8, 11

5

  1. 40

  2. 52

  3. y

  4. Symmetric

  5. Skewed right

6

  1. 16

  2. 22

  3. y, its range is larger

  4. yes, I believe it’s at about 29

  5. Left skewed

7

dat1 <- c(60,68,77,89,98)

boxplot(dat1)

8

dat2 <- c(110,140,157,173,205)

boxplot(dat2)

9

dat3 <- c(42,43,46,46,47,
         47,48,49,49,50,
         50,51,51,51,51,
         52,52,54,54,54,
         54,54,55,55,55,
         55,56,56,56,57,
         57,57,57,58,60,
         61,61,61,62,64,
         64,65,68,69)

  1. By hand = 42, 50.5, 54.5, 57.5, 69

boxplot(dat3)

  1. Symmetric with an outlier

10

dat3 <- c(7.2, 7.8, 7.8, 7.9, 8.1, 8.3,
          8.5, 8.6, 8.6, 8.6, 8.7, 8.8,
          9.0, 9.1, 9.2, 9.2, 9.2, 9.4,
          9.4, 9.6, 9.7, 9.7, 9.9, 9.9,
          10.0, 10.0, 10.0, 10.1, 10.2, 10.3,
          10.0, 10.3, 10.3, 10.7, 10.7, 10.9,
          11.2, 11.2, 11.2, 11.3, 11.3, 11.3,
          11.5, 11.5, 11.7, 12.4, 12.5, 13.6,
          13.8, 14.4, 16.4)

  1. 1.2, 7.2, 9, 10, 16.4

boxplot(dat3)

  1. Slightly right skewed