1.A survey from teenage research unlimited found that 80% of teenage consumers received their spending money from part-time jobs. If five teenagers are selected at random, find the probability that at least three of them will have part-time jobs
2.PMEA associate market research found that 40% of Nigerians don’t think that having a college education is important to succeed in the business world, if a random sample of five Nigerians are selected, find these probabilities
A.That exactly 2 people will agree with that statement
B.At most 3 people will agree with that statement
C.At least 2 people will agree with that statement
D.Fewer than 3 people will agree with that statement
That none of the people will agree with that statement
1. Let "X=" the number of teenagers who will have part-time jobs: "X\\sim Bin (n, p)."
Given "n=5, p=0.8, q=1-p=0.2"
"=\\dbinom{5}{3}(0.8)^3(0.2)^{5-3}+\\dbinom{5}{4}(0.8)^4(0.2)^{5-4}"
"+\\dbinom{5}{5}(0.8)^5(0.2)^{5-5}=0.2048+0.4096+0.32768"
"=0.94208"
2. Let "X=" the number of people who will agree with that statement: "X\\sim Bin (n, p)."
Given "n=5, p=0.4, q=1-p=0.6"
A.
B.
"=1-\\dbinom{5}{4}(0.4)^4(0.6)^{5-4}+\\dbinom{5}{5}(0.4)^5(0.6)^{5-5}"
"=1-0.0768-0.01024=0.91296"
C.
"=1-\\dbinom{5}{0}(0.4)^0(0.6)^{5-0}+\\dbinom{5}{1}(0.4)^1(0.6)^{5-1}"
"=1-0.07776-0.2592=0.66304"
D.
"=\\dbinom{5}{0}(0.4)^0(0.6)^{5-0}+\\dbinom{5}{1}(0.4)^1(0.6)^{5-1}"
"+\\dbinom{5}{2}(0.4)^2(0.6)^{5-2}"
"=0.07776+0.2592+0.3456=0.68256"
E.
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