probability and statistics
McGraw-Hill/Irwin
Copyright © 2008 by The McGraw-Hill Companies, Inc. All rights reserved.
Chapter 3
Probability and Statistics
A Foundation for Becoming a More Effective and Efficient Problem Solver
3-*
Normal Distribution
- Common probability distribution
- e.g., height, weight, age, sum of two dice rolled 1,000 times, etc.
3-*
Normal Distribution
Sheet: Chart1
Sheet: Sheet1
Sheet: Sheet2
Sheet: Sheet3
Sheet: Sheet4
Sheet: Sheet5
Sheet: Sheet6
Sheet: Sheet7
Sheet: Sheet8
Sheet: Sheet9
Sheet: Sheet10
Sheet: Sheet11
Sheet: Sheet12
Sheet: Sheet13
Sheet: Sheet14
Sheet: Sheet15
Sheet: Sheet16
0.0
0.1
0.2
0.30000000000000004
0.4
0.5
0.6
0.7
0.7999999999999999
0.8999999999999999
0.9999999999999999
1.0999999999999999
1.2
1.3
1.4000000000000001
1.5000000000000002
1.6000000000000003
1.7000000000000004
1.8000000000000005
1.9000000000000006
2.0000000000000004
2.1000000000000005
2.2000000000000006
2.3000000000000007
2.400000000000001
2.500000000000001
2.600000000000001
2.700000000000001
2.800000000000001
2.9000000000000012
3.0000000000000013
3.1000000000000014
3.2000000000000015
3.3000000000000016
3.4000000000000017
3.5000000000000018
3.600000000000002
3.700000000000002
3.800000000000002
3.900000000000002
4.000000000000002
4.100000000000001
4.200000000000001
4.300000000000001
4.4
4.5
4.6
4.699999999999999
4.799999999999999
4.899999999999999
4.999999999999998
5.099999999999998
5.1999999999999975
5.299999999999997
5.399999999999997
5.4999999999999964
5.599999999999996
5.699999999999996
5.799999999999995
5.899999999999995
5.999999999999995
6.099999999999994
6.199999999999994
6.299999999999994
6.399999999999993
6.499999999999993
6.5999999999999925
6.699999999999992
6.799999999999992
6.8999999999999915
6.999999999999991
7.099999999999991
7.19999999999999
7.29999999999999
7.39999999999999
7.499999999999989
7.599999999999989
7.699999999999989
7.799999999999988
7.899999999999988
7.999999999999988
1.3383022576488534E-4
1.986554713927727E-4
2.919469257914602E-4
4.247802705507514E-4
6.119019301137718E-4
8.726826950457599E-4
0.0012322191684730197
0.001722568939053681
0.00238408820146484
0.0032668190561999178
0.0044318484119380075
0.005952532419775848
0.007915451582979967
0.01042093481442259
0.013582969233685632
0.017528300493568537
0.022394530294842927
0.028327037741601183
0.03547459284623148
0.043983595980427226
0.0539909665131881
0.06561581477467664
0.07895015830089423
0.09404907737688703
0.11092083467945568
0.1295175956658919
0.14972746563574504
0.17136859204780758
0.19418605498321317
0.21785217703255083
0.2419707245191437
0.26608524989875515
0.28969155276148306
0.3122539333667616
0.33322460289179995
0.3520653267642998
0.36827014030332356
0.3813878154605243
0.391042693975456
0.3969525474770118
0.39894228040143265
0.3969525474770117
0.39104269397545577
0.38138781546052397
0.3682701403033232
0.35206532676429947
0.33322460289179967
0.3122539333667614
0.28969155276148295
0.26608524989875515
0.24197072451914378
0.21785217703255105
0.1941860549832135
0.17136859204780797
0.14972746563574552
0.1295175956658924
0.11092083467945624
0.0940490773768876
0.07895015830089482
0.0656158147746772
0.053990966513188625
0.04398359598042771
0.0354745928462319
0.02832703774160159
0.022394530294843257
0.01752830049356885
0.013582969233685878
0.010420934814422817
0.007915451582980144
0.005952532419776001
0.004431848411938125
0.003266819056200014
0.0023840882014649163
0.0017225689390537363
0.0012322191684730624
8.726826950457925E-4
6.119019301137963E-4
4.247802705507695E-4
2.9194692579147323E-4
1.9865547139278204E-4
1.3383022576489198E-4
0.0
1.3383022576488534E-4
0.1
1.986554713927727E-4
0.2
2.919469257914602E-4
0.30000000000000004
4.247802705507514E-4
0.4
6.119019301137718E-4
0.5
8.726826950457599E-4
0.6
0.0012322191684730197
0.7
0.001722568939053681
0.7999999999999999
0.00238408820146484
0.8999999999999999
0.0032668190561999178
0.9999999999999999
0.0044318484119380075
1.0999999999999999
0.005952532419775848
1.2
0.007915451582979967
1.3
0.01042093481442259
1.4000000000000001
0.013582969233685632
1.5000000000000002
0.017528300493568537
1.6000000000000003
0.022394530294842927
1.7000000000000004
0.028327037741601183
1.8000000000000005
0.03547459284623148
1.9000000000000006
0.043983595980427226
2.0000000000000004
0.0539909665131881
2.1000000000000005
0.06561581477467664
2.2000000000000006
0.07895015830089423
2.3000000000000007
0.09404907737688703
2.400000000000001
0.11092083467945568
2.500000000000001
0.1295175956658919
2.600000000000001
0.14972746563574504
2.700000000000001
0.17136859204780758
2.800000000000001
0.19418605498321317
2.9000000000000012
0.21785217703255083
3.0000000000000013
0.2419707245191437
3.1000000000000014
0.26608524989875515
3.2000000000000015
0.28969155276148306
3.3000000000000016
0.3122539333667616
3.4000000000000017
0.33322460289179995
3.5000000000000018
0.3520653267642998
3.600000000000002
0.36827014030332356
3.700000000000002
0.3813878154605243
3.800000000000002
0.391042693975456
3.900000000000002
0.3969525474770118
4.000000000000002
0.39894228040143265
4.100000000000001
0.3969525474770117
4.200000000000001
0.39104269397545577
4.300000000000001
0.38138781546052397
4.4
0.3682701403033232
4.5
0.35206532676429947
4.6
0.33322460289179967
4.699999999999999
0.3122539333667614
4.799999999999999
0.28969155276148295
4.899999999999999
0.26608524989875515
4.999999999999998
0.24197072451914378
5.099999999999998
0.21785217703255105
5.1999999999999975
0.1941860549832135
5.299999999999997
0.17136859204780797
5.399999999999997
0.14972746563574552
5.4999999999999964
0.1295175956658924
5.599999999999996
0.11092083467945624
5.699999999999996
0.0940490773768876
5.799999999999995
0.07895015830089482
5.899999999999995
0.0656158147746772
5.999999999999995
0.053990966513188625
6.099999999999994
0.04398359598042771
6.199999999999994
0.0354745928462319
6.299999999999994
0.02832703774160159
6.399999999999993
0.022394530294843257
6.499999999999993
0.01752830049356885
6.5999999999999925
0.013582969233685878
6.699999999999992
0.010420934814422817
6.799999999999992
0.007915451582980144
6.8999999999999915
0.005952532419776001
6.999999999999991
0.004431848411938125
7.099999999999991
0.003266819056200014
7.19999999999999
0.0023840882014649163
7.29999999999999
0.0017225689390537363
7.39999999999999
0.0012322191684730624
7.499999999999989
8.726826950457925E-4
7.599999999999989
6.119019301137963E-4
7.699999999999989
4.247802705507695E-4
7.799999999999988
2.9194692579147323E-4
7.899999999999988
1.9865547139278204E-4
7.999999999999988
1.3383022576489198E-4
3-*
Mean and Standard Deviation
- Most common statistics used
- Mean or expected value
E(x) = SxiP(xi)
- Standard deviation
s(x) = [S [xi - E(x)]2P(xi)]0.5
s(x) = [S [xi - m]2/n-1]0.5
3-*
Z-Scores
- Standard Z-score
- Measures the number of standard deviations away from the mean
- Calculated as such:
- Look up Z value in table to find probability
Normal Distribution
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0
1
2
3
4
5
6
7
8
x
P(x)
Normal Distribution
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0
1
2
3
4
5
6
7
8
x
P(x)
mean = 4, std. dev. = 1
-1 std. dev.
+1 std. dev.
68% of values
m
=
x
i
å
n
Z
=
x
-
mean
SD