What is the expected probability of randomly selecting a black marble from the bag in one attempt?

Question

Number of times selected
White 8
Red 14
Black 9
Blue 5

Answer 1

To find the probability of selecting a black marble in one attempt, we first need to calculate the total number of marbles in the bag:

Total number of marbles = 8 (white) + 14 (red) + 9 (black) + 5 (blue) = 36

Then, we calculate the probability of selecting a black marble:

Probability = Number of black marbles / Total number of marbles
Probability = 9 / 36
Probability = 1 / 4
Probability = 0.25 or 25%

Therefore, the expected probability of randomly selecting a black marble from the bag in one attempt is 25%.