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The following is the number of each color of M&M found in a sample bag of 280 M&

ID: 2934509 • Letter: T

Question

The following is the number of each color of M&M found in a sample bag of 280 M&M’s.

Red-39

Orange-58

Yellow-55

Green-38

Blue-27

Brown-63

Suppose you reach into the bag and randomly select one M&M. Calculate the following

probabilities. Round your answers to 4 decimals.

1.

P (Red) =

2.

P (Yellow) =

3.

P (Blue) =

Suppose you reach into the sample bag and randomly select THREE M&M’s.

Calculate the following probabilities (with and without replacement).

Show your calculations and round your final answers to 4 decimals.

4.

The probability that the first M&M is Red, the second M&M is Yellow, and the third M&M is Blue.

(with replacement)

5.

The probability that the first M&M is Red, the second M&M is Yellow, and the third M&M is Blue.

(without replacement)

6.

The probability that all three M&M’s are Blue.

(with replacement)

7.

The probability that all three M&M’s are Blue.

(without replacement)

8.

Would it be unusual for all three M&M’s to be blue if the sampling is done without replacement?

Justify your answer using a complete sentence and proper grammar.

Explanation / Answer

(1) P(Red) = 39/280 = 0.1393

(2) P(Yellow) = 55/280 = 0.1964

(3) P(Blue) = 27/280 = 0.0964

(4) With Replacement:
P(RYB) = (39/280) X (55/280) X (27/280)
REASON: Since Replacement, Total remains as 280 throughout)

              = 0.1393 X 0.1964 X 0.0964 = 0.002637

(5) Without Replacement - 280 becomes 279 & 278 after each selection)

P(RYB) = (39/280) X (55/279) X (27/278) = 0.1393 X 0.1971 X 0.0971 = 0.002666

(6) With Replacement:

P(BBB) := (27/280) X (27/280) X (27/280) = 0.09643 = 0.0008958

(7) Without Replacement:
P(BBB) = (27/280) X (26/279) X (25/278) = 0.0964 X 0.0932 X 0.0899 = 0.0008708

(8) Since the probability of all three M&M's to be blue if the sampling is done without replacement = 0.0008708 is extremely small, it would be unusual.