97.6k views
2 votes
Needing help with the rest of the questions in the photo. Please help ! Thank you

Needing help with the rest of the questions in the photo. Please help ! Thank you-example-1

1 Answer

1 vote

The mean of a discrete random variale is given by the formula:


\mu=E(X)=\sum xP(x)

Thus, we have:


\begin{gathered} \mu=(1*0.07)+(2*0.07)+(9*0.11)*(12*0.52)*(14*0.12)+(19*0.11) \\ \end{gathered}
\begin{gathered} \mu=0.07+0.14+0.99+6.24+1.68+2.09 \\ \mu=11.21 \end{gathered}

The variance of a discrete random variable is given by the formula:


\begin{gathered} \sigma^2=\sum (x-\mu)^2P(x) \\ \end{gathered}

Thus, we have:


\sigma^2=\lbrack(1-11.21)^2*0.07\rbrack+\lbrack(2-11.21)^2*0.07\rbrack+\lbrack(9-11.21)^2*0.11\rbrack+\lbrack(12-11.21)^2*0.52\rbrack+\lbrack(14-11.21)^2*0.12\rbrack+\lbrack(19-11.21)^2*0.11\rbrack
\begin{gathered} \sigma^2=7.297+5.938+0.5373+0.3245+0.9341+6.6753 \\ \sigma^2=21.706 \end{gathered}

The standard deviation is given as:


\begin{gathered} \sigma=\sqrt[]{\sigma^2} \\ \sigma=\sqrt[]{21.706} \\ \sigma=4.659 \end{gathered}

The Expected value of X is the mean, = 11.21

User Yashdeep Patel
by
7.5k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories