HK301 Assignment 2
Mark Donald 201101136
October 9th, 2013
3.2.30.5*0.513 = 0.257
The probability of a newborn having the disease is 0.257
3.2.7a-0.1*0.92= 0.092
0.9*0.06= .054
0.092+0.054= 0.146
The probability of a person, randomly chosen, testing positive is 0.146
b-0.092/0.146= 0.63
If a person tests positive, there is a 0.63 probability that they have the disease
3.3.3a-1016/6549= 0.155
There is a 0.155 probability that someone in the study is stressed.
b-216/2115= 0.102
There is a 0.102 probability that a member of the high income group is stressed.
c-The high income and stressed groups are independent, because the probabilities for a and b are
different.
3.3.4
a- 2480/6549= 0.379
There is a probability of 0.379 that someone in the study has low income
b-(2480+526+1016/6549)= 0.614
c- (1016+1954)/ 6549= 0.454
There is a 0.454 probability that someone is either in the stressed or low income groups.
3.3.5-Yes, they are independent. The removal of one will have no statistical difference on the other.
3.4.2-a-0.12+0.25+0.33+0.20+0.03=0.93
There is a 0.93 probability that the diameter is less than 10
b-0.33+0.25+0.12+0.07= 0.77
There is a 0.77 probability that the diameter is greater than 4
c- 0.20+0.33+0.25=0.78
There is a 0.78 probability that the diameter is between 2 and 8
3.5.1a-610/5000=0.122
b- 160/5000=0.032
c-3910/5000= 0.782
3.5.7-(0*0.15)+(1*0.5)+(2*0.35)= 1.2
3.5.8- (((0-1.2)2(0.15))+((1-1.2)2(0.5))+((2-1.2)2(0.35)))=0.46
That is the variance. The square root of this, the standard deviation, is 0.678
3.6.1- a- The probability of 3 yellow and 1 green is 0.422
b- the probability of all four being yellow is 0.316
c- the probability of a four being the same colour is 0.320
3.6.2
a- Pr (Y = 0) = 0.113
b-Pr (Y =1) = 0.328
c-Pr (Y=2) = 0.356
d-Pr (0≤Y≥2) = 0.113 + 0.328 + 0.356 = 0.797
e-Pr (0<Y≥2)= 0.797 – 0.113 = 0.684
3.7.2
Dead
embryos Live embryos
Expected frequency
0
9
0.391
1
8
0.387
2
7
0.17
3
6
0.044
4
5
0.007
5
4
0.001
6
3
0
7
2
0
8
1
0
9
0
0
The observed results do not contradict the classical assumption
3.S.6-a- (50C0)(0.01)0(0.90)50= 0.005
b- 1-0.005 = 0.995
3.S.8- 6C4(0.25)4(0.752)= 0.0104
3.S.9-a- 0.41 + 0.25 = 0.66
b- 0.01 + 0.20 = 0.21
c- 0.25+ 0.09 + 0.04 = 0.38
3.S.10- a- 4C4(0.38)4 =0.02
b- 4C3(0.38)3(0.62)1= 0.136