Basic Applied Statistics 200
Solutions to Practice Midterm 1

1.  
   1. (iii)more than
   2. (iii) more variable
   3. (iii) skewed right
   4. (iii) more
   5. (i) Five Number Summary because mean and s.d. would be distorted by outliers
2. 1. Use stems 0,0,1,1,2 or 0,0,0,0,0,1,1,1,1,1,2
   2. no; neither stemplot is bell-shaped
   3. 1, 2.5, 10, 13.5, 20
   4. 6: this is the typical distance of values from their mean: 1 would be too small, 16 too large
3.  
   1. z>.44 same as z<-.44; proportion is .3300
   2. .0228-.0013=.0215
   3. -1.64 or -1.65
4. 1. between 270 and 730
   2. x<300 same as z<(300-500)/115=-1.74; proportion is .0409
   3. the mean, 500
   4. .15 above same as .85 below; z=1.04 so x=500+1.04(115)=619.6
5. 1. MALES: 13/20=.65 vs.females 19/54=.35
   2. 35/42=.83
   3. 35/74=.47
6.  
   1. height
   2. (i) positive (iii) linear (v) strong
   3. positive square root of .623 = .79
   4. same because r is independent of units
   5. -15.4+.364(67) = 9
   6. observed minus predicted = 8-9 = -1
   7. (iii) because minitab shows R and X
   8. increase
   9. (i) (see first paragraph page 119)
7. 1. (i) observational study; you can't make teens be adjusted or eat with their families
   2. (i)
   3. (iii)
8. 1. Pitt students
   2. 3 times 2 = 6
9. 1. (ii)
   2. (i)
   3. (i)

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