Probabilities

[Mizi]

The following table summarizes the results of a poll taken of CEOs and analysts concerning the economic impact of a pending piece of
legislation:
Group
Think it will have a
positive impact
Think it will have a
negative impact
Total
CEO’s 40 30 70
Analysts 70 60 130
110 90 200
What is the probability that a randomly selected individual from this group will be an analyst that thinks that the legislation will have a
positive impact on the economy?
0.30.
0.45.
0.35.
Explanation
70 analysts / 200 individuals = 0.35.


Can anyone explain this further

 

[Oscar]

P(Analyst ∪ Positive) = 70/200 = 0.35 = 35%
From the table you know that you have 70 analysts who think that the legislation will be positive. The probability of randomly selecting one of these 70 analysts out of the total 200 interviewed persons (population) is simply 70 divided by 200.