It has been stated that 40% of the general population donate their time and energy to working on
community projects. Suppose 15 people have been randomly sampled from a community and
asked if they donated their time and energy to community projects. Let x be the number of them
that do donate their time and energy to community projects. Find the probability that more than
seven of the 15 do donate their time and energy to community projects
Solution
Given X~Binomial(n=15, p=0.4) P(X=x)=xC15*(0.4^x)*(0.6^(15-x)) SO the
probability is P(X>7)=P(X=8)+P(X=9)+...+P(X=15)=0.2131032.
It has been stated that 40 of the general population donate their t.pdf
1. It has been stated that 40% of the general population donate their time and energy to working on
community projects. Suppose 15 people have been randomly sampled from a community and
asked if they donated their time and energy to community projects. Let x be the number of them
that do donate their time and energy to community projects. Find the probability that more than
seven of the 15 do donate their time and energy to community projects
Solution
Given X~Binomial(n=15, p=0.4) P(X=x)=xC15*(0.4^x)*(0.6^(15-x)) SO the
probability is P(X>7)=P(X=8)+P(X=9)+...+P(X=15)=0.2131032
