In: Statistics and Probability
A service station has both self-service and full-service islands. On each island, there is a single regular unleaded pump with two hoses. Let X denote the number of hoses being used on the self-service island at a particular time, and let Y denote the number of hoses on the full-service island in use at that time. The joint pmf of X and Y appears in the accompanying tabulation.
| y | ||||
| 
 p(x, y)  | 
0 | 1 | 2 | |
| x | 0 | 0.10 | 0.05 | 0.01 | 
| 1 | 0.06 | 0.20 | 0.08 | |
| 2 | 0.05 | 0.14 | 0.31 | |
(a) Given that X = 1, determine the conditional pmf of Y—i.e., pY|X(0|1), pY|X(1|1), pY|X(2|1). (Round your answers to four decimal places.)
| y | 0 | 1 | 2 | 
| pY|X(y|1) | 
(b) Given that two hoses are in use at the self-service island,
what is the conditional pmf of the number of hoses in use on the
full-service island? (Round your answers to four decimal
places.)
| y | 0 | 1 | 2 | 
| pY|X(y|2) | 
(c) Use the result of part (b) to calculate the conditional
probability P(Y ≤ 1 | X = 2). (Round
your answer to four decimal places.)
P(Y ≤ 1 | X = 2) =
(d) Given that two hoses are in use at the full-service island,
what is the conditional pmf of the number in use at the
self-service island? (Round your answers to four decimal
places.)
| x | 0 | 1 | 2 | 
| pX|Y(x|2) |