Answer: 0.0018
Step-by-step explanation:
Binomial distribution formula :-
[tex]P(x)=^nC_xp^x(q)^{n-x}[/tex], here P(x) is the probability of getting success at x trial , n is the total number of trails, p is the probability of getting success in each trail.
Given : The probability that a child in the U.S. was living with both parents : p=0.70 ; q=1-0.70=0.30
If 25 children were selected at random in the U.S.,then the probability that at most 10 of them will be living with both of their parents will be :-
[tex]P(x\leq10)=P(0)+P(1)+P(2)+P(3)+P(4)+P(5)+P(6)+P(7)+P(8)+P(9)+P(10)\\\\=^{25}C_{0}(0.7)^0(0.3)^{25}+^{25}C_{1}(0.7)^1(0.3)^{24}+^{25}C_{2}(0.7)^2(0.3)^{23}+^{25}C_{3}(0.7)^3(0.3)^{22}+^{25}C_{4}(0.7)^4(0.3)^{21}+^{25}C_{5}(0.7)^5(0.3)^{20}+^{25}C_{6}(0.7)^6(0.3)^{19}+^{25}C_{7}(0.7)^7(0.3)^{`18}+^{25}C_{8}(0.7)^8(0.3)^{17}+^{25}C_{9}(0.7)^9(0.3)^{16}+^{25}C_{10}(0.7)^{10}(0.3)^{15}\\\\=(0.7)^0(0.3)^{25}+25(0.7)^1(0.3)^{24}+300(0.7)^2(0.3)^{23}+2300(0.7)^3(0.3)^{22}+ 12650(0.7)^4(0.3)^{21}+53130(0.7)^5(0.3)^{20}+177100(0.7)^6(0.3)^{19}+480700(0.7)^7(0.3)^{`18}+1081575(0.7)^8(0.3)^{17}+2042975(0.7)^9(0.3)^{16}+3268760(0.7)^{10}(0.3)^{15}\\\\=0.00177840487034\approx0.0018[/tex]
Hence, the probability that at most 10 of them will be living with both of their parents is 0.0018.