3.2

5 s^2=36, s=6

6 s^2=100, s=10

7 p^2=16, p=4

8 p^2=64, p=8

9 s^2=196, s=14

10 p^2=25, p=5

14 s^2=71, s=8.43

3.4

5 -.30; -.43; The 40-week baby weighs less

7 The man is relatively taller

9 Clayton Kershaw had better relative to Felix Hernandez because Kershaw’s ERA was 2.30 standard deviations below the mean ERA. While Hernandez’s ERA was only 1.91 standard deviations below the american league’s mean ERA.

11 Ryan is 3.39 standard deviations below the mean in the 100m whereas in the 200m he was he had a standard deviation of 3.05 below the mean. Therefore he is better at the 100m race.

13 239

15

  1. 15% of males 3 to 5 months of age have a head circumference of 41.0 cm or less. 85% of males 3 to 5 months of age have a head circumference that is larger than 41.0 cm.

  2. 90% of females 2 years of age have a waist cirumcerence of 52.7 cm or less. 10% of females 2 years of age have a waist circumference that is more than 52.7 cm.

  3. The heights at each percentile decrease as the age increases. Therefore as age increases males get taller.

22

  1. 1.21 standard deviations below the mean.

  2. Q1=9.95 g/dL, Q2=9.15 g/dL, Q3=11.1 g/dL

  3. 1.95 g/dL

  4. LF=6.225 g/dL, UF=14.025g/dL

25 The cutoff point is 574 minutes.

3.5

3

  1. skewed right

  2. 0,1,3,6,16

4

  1. Bell shaped

  2. -1,2,5,7,11

5

  1. 40

  2. 52

  3. y, spread out among more numbers

  4. Symmetric

  5. skewed right

6

  1. M=16

  2. Q1=22

  3. variable y has more dispersion

  4. outlier is 30

  5. skewed left

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. Five summary = 42, 50.5, 54.5, 57.5, 69

boxplot(dat3)

  1. median is near the center of the box so therefore, the distribution is symmetric, with an outlier