csat-suneung 2014 Q9

csat-suneung · South-Korea · csat__math-A 3 marks Binomial Distribution Find Parameters from Moment Conditions
A random variable $X$ follows a binomial distribution $\mathrm { B } ( 9 , p )$, and $\{ \mathrm { E } ( X ) \} ^ { 2 } = \mathrm { V } ( X )$. What is the value of $p$? (Here, $0 < p < 1$) [3 points]
(1) $\frac { 1 } { 13 }$
(2) $\frac { 1 } { 12 }$
(3) $\frac { 1 } { 11 }$
(4) $\frac { 1 } { 10 }$
(5) $\frac { 1 } { 9 }$
A random variable $X$ follows a binomial distribution $\mathrm { B } ( 9 , p )$, and $\{ \mathrm { E } ( X ) \} ^ { 2 } = \mathrm { V } ( X )$. What is the value of $p$? (Here, $0 < p < 1$) [3 points]\\
(1) $\frac { 1 } { 13 }$\\
(2) $\frac { 1 } { 12 }$\\
(3) $\frac { 1 } { 11 }$\\
(4) $\frac { 1 } { 10 }$\\
(5) $\frac { 1 } { 9 }$