Statistics in a Modern World 800
Solutions to Practice Exam 3
 1.3=.7

 yes; you can be male or female but not both
 yes; .6*.5=.3
 .6+.5.3=.8
 1.8=.2

 (a) 1/2
 (ii) gambler's fallacy

 (a) 1/4 * 1/4 = 1/16
 (ii) independent

 5/6 * 5/6 = 25/36=.69
 1  25/36 = 11/36 = .31
 (i) relative frequency
 1(.1)+2(.5)+3(.3)+4(.1)=2.4
 (c)
 (v) optimism
 (a) anchoring
 (b) second is different from the first and third is different
from both of them
 (c) this is the opposite of #10
 (g) conservatism
 (g) pseudocertainty effect
 (a) (more general)
 (d) representativeness
 (c)
 (b)

 first branchoff: spy or not spy, with probabilities .001 and .999;
second branchoff: incriminated or not, with probabilities .8 and .2
for the spies, .16 and .84 for the nonspies
 .001(.8)=.0008
 .999(.16)=.15984
 .0008+.15984=.16064
 .0008/.16064=.00498
 (d) confusion of the inverse
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