Question

Surgery Satisfaction Survey

Surgery Satisfied Dissatisfied Total
Knee 70 25 95
Hip 90
15 105
Total 160 40 200
The table shows survey results for 200 patients who had either hip or knee surgery. If one person is selected randomly, what is the
probability he or she was dissatisfied, given that he or she had hip surgery? (Round to the nearest tenth of a percent.)
A)
44.2%
B)
38.6%
0
21.7%
D)
14.3%

Answer 1

Answer: D) 14.3%

Explanation:

Conditional probability formula:

`P(B |\text{given that A}) =(P(A\ and\ B))/(P(A))`

So, The probability he or she was dissatisfied, given that he or she had hip surgery =
`\frac{\text{Number of persons are dissatisfied and has hip surgery}}{\text{Total persons have hip surgery}}`

From the table, the number of persons who are dissatisfied and has hip surgery = 15

Total persons have hip surgery = 105

Required probability =
`(15)/(105)\approx0.143`

In percent, Required probability = 14.3%

Correct option D) 14.3%