Question

Please help me with this

Answer 1

Prob ( guessing right) = 0.25 . Get 1 point.

Prob( guessing wrong) = 0.75. Lose 0.5 points.

Expected value = 1(0.25) + (-0.5)(0.75)

= -0.125 answer

Answer 2

The expected value of the guess is:

-0.125

Explanation:

We know that for each answer there is one correct choice and 3 incorrect choice.

Hence,

`P(correct\ answer)=(1)/(4)`

and

`P(incorrect\ answer)=(3)/(4)`

Also, 1 point is awarded for each correct response and 0.5 is deducted for each incorrect response.

Hence, the expected value of the guess is calculated by:

`Expected\ Value=P(correct\ answer)* 1+P(incorrect\ answer)* (-0.5)\\\\i.e.\\\\Expected\ Value=(1)/(4)+(3)/(4)* (-0.5)\\\\i.e.\\\\Expected\ Value=(1)/(4)-(1.5)/(4)\\\\i.e.\\\\Expected\ Value=(-0.5)/(4)\\\\i.e.\\\\Expected\ Value=-0.125`