Answer:
Option C) 2.78 Â Â Â Â Â Â Â Â Â Â Â Â
Step-by-step explanation:
We are given the following in the question:
Grade: Â Â Â Â Â Â Â A Â Â Â B Â Â Â Â C Â Â Â D Â Â Â Â F
Value: Â Â Â Â Â Â Â 4 Â Â Â 3 Â Â Â Â 2 Â Â Â Â 1 Â Â Â Â 0
Probability: Â Â 0.20 Â 0.50 Â 0.30 Â 0.08 Â 0.02
We have to find the expected value.
Formula:
[tex]E(x) = \displaystyle\sum x_iP(x_i)\\\\E(x) = 4(0.20) + 3(0.50) + 2(0.20) + 1(0.08) + 0(0.02)\\\\E(x) =2.78[/tex]
Thus, the correct answer is
Option C) 2.78