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Question Number 76726 by Rio Michael last updated on 29/Dec/19

$$\mathrm{var}\left(\mathrm{x}\right)=2\mathrm{then}\mathrm{var}(2\mathrm{x}-3)=?$$$$\mathrm{E}\left(\mathrm{x}\right)=2\mathrm{then}\mathrm{E}(2\mathrm{x}-3)=?$$

Answered by john santu last updated on 30/Dec/19

$$E\left(x\right)=\sum _{x}xf\left(x\right)=2$$$$soE(2x-3)=\sum _x(2x-3)f\left(x\right)$$$$=2\sum _{x}xf\left(x\right)-\sum _{x}3f\left(x\right)$$$$=4-3\sum _{x}f\left(x\right)$$

Commented by john santu last updated on 30/Dec/19

$$note:\sum _{x}f\left(x\right)=1$$

Answered by benjo 1/2 santuyy last updated on 30/Dec/19

$$usingbytheorem$$$$E(2x-3)=2E\left(x\right)-3$$$$sowegetE(2x-3)=2\times 2-3=1$$

Answered by benjo 1/2 santuyy last updated on 30/Dec/19

$$var(2x-3)=2^{2}var\left(x\right)=4\times 2=8$$

Commented by Rio Michael last updated on 30/Dec/19

$$\mathrm{thanks}\mathrm{guys}$$

Commented by john santu last updated on 30/Dec/19

$$yourwelcomebro$$

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