10 The best estimate of the standard deviation of the mens
weights displayed in this dotplot is 1. 10 2. 15 3. 20 4. 40
Slide 12
Slide 13
12 Z-scores: Standardized Data Values Measures the distance of
a number from the mean in units of the standard deviation
Slide 14
13 z-score corresponding to y
Slide 15
14 n Exam 1: y 1 = 88, s 1 = 6; exam 1 score: 91 Exam 2: y 2 =
88, s 2 = 10; exam 2 score: 92 Which score is better?
Slide 16
15 Comparing SAT and ACT Scores n SAT Math: Eleanors score 680
SAT mean =500 sd=100 n ACT Math: Geralds score 27 ACT mean=18 sd=6
n Eleanors z-score: z=(680-500)/100=1.8 n Geralds z-score:
z=(27-18)/6=1.5 n Eleanors score is better.
Slide 17
16 Z-scores add to zero Student/Institutional Support to
Athletic Depts For the 9 Public ACC Schools: 2013 ($ millions)
SchoolSupporty - ybarZ-score Maryland15.56.41.79 UVA13.14.01.12
Louisville10.91.80.50 UNC9.20.10.03 VaTech7.9-1.2-0.34
FSU7.9-1.2-0.34 GaTech7.1-2.0-0.56 NCSU6.5-2.6-0.73
Clemson3.8-5.3-1.47 Mean=9.1000, s=3.5697 Sum = 0
Slide 18
17 In 2007-08 the mean tuition at 4-yr public
colleges/universities in the U.S. was $6185 with a standard
deviation of $1804. In NC the mean tuition was $4320. What is NCs
z-score? 1. 1.03 2. -1.03 3. 2.39 4. 1865 5. -1865