Standard Deviation of the Sum of Random Variables
The probability distributions for two independent random variables, X and Y, are shown in the tables below. What is the standard deviation of the sum W = X + Y? (Round your answer to two decimal places.)
Distribution of X
| Card Value (X) | Probability |
|---|---|
| 1 | 0.25 |
| 9 | 0.25 |
| 20 | 0.25 |
| 74 | 0.25 |
Distribution of Y
| Card Value (Y) | Probability |
|---|---|
| 5 | 0.3333 |
| 15 | 0.3333 |
| 55 | 0.3334 |
A
10.50
B
26.00
C
35.78
D
51.00
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