Answer: 0.6472
Step-by-step explanation:
Given: The proportion of unvaccinated school-age children = 13.5%
Then, the proportion of vaccinated school-age children :p=100%-13.5%
= 86.5% = 0.865
Total children selected :n=3
Binomial probability formula:
[tex]P(X=x)=\ ^nC_xp^x(1-p)^{n-x}[/tex]
The probability that all three children have been vaccinated :
[tex]P(X=3)=\ ^3C_3(0.865)^3(0.135)^0\\=(1)(0.647214625)\approx0.6472[/tex]
Hence, the required probability = 0.6472