Answer and Explanation
Your Answer is
Correct Answer is D
Explanation
According to the meaning of the question, the first matrix (1×4) is the sports, and the second matrix (4×1) is the probability of winning in each sport. For the expectation of the total number of medals, you can use the expectation formula:
N=(40*0.3)+(60×0.4)+(80×0.2)+(80×0.5)=12+ 24+16+40=92
That is, the number of medals in the autumn games is estimated to be 92. The answer is D.