SOLUTION: Submit your answers to the following binomial questions. You may use the appendix tables 5 to answer parts a and b. According to a government study,15% of all children live in a ho

Algebra ->  Probability-and-statistics -> SOLUTION: Submit your answers to the following binomial questions. You may use the appendix tables 5 to answer parts a and b. According to a government study,15% of all children live in a ho      Log On


   

Question 1083878: Submit your answers to the following binomial questions. You may use the appendix tables 5 to answer parts a and b. According to a government study,15% of all children live in a household that has an income below the poverty level. If a random sample of 20 children is selected:
a) what is the probability that 5 or more live in poverty?
b) what is the probability that 5 live in poverty?
c) what is the expected number (mean) that live in poverty?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
expected value is x*p(x)=0.15*20=3
exactly 5 is 20C5(0.15^5)(0.85^15)=0.1028
5 or greater. Do 0 to 4
4 is 20C4(.15^4*.85^16)=0.1821
3 is 20C3(.15^3*.85^17)=0.2428
2 is 190 etc. 0.2293
1 is 20*.15*.85^19=0.1368
0 is .85^20=0.0388
Total is 0.9326
5 or greater is 1-0.9326=0.0674