Answer:
The whole angle on a circle is equal to 360°.
This means that:
∠A + ∠B = 360°.
Here we know that ∠A = 7°
Then ∠B = 360° - 7° = 353°
Now, if the probability is evenly distributed for all the angles, then the probability that the spinner lands in A is equal to the quotient between the measure of the angle A, and the measure of the total circumference, this will be:
Pa = 7°/360° = 0.019
And the same for B:
Pb = 353°/360° = 0.981
Now, the expected value can be calculated as:
Ev = ∑xₙ*pₙ
Where xₙ is the event n, and pₙ is its probability.
Then:
x₁ = A = 100
p₁ = Pa = 0.019
x₂ = B = 2
p₂ = Pb = 0.981
The expected vale will be:
Ev = 100*0.019 + 2*0.981 = 3.862
Rounding to the nearest hundredth, the second digit after the decimal point, we have:
Ev = 3.86
