Basicaly the Q is:
30% use Mac, 50% use Windows, 20% use Linux.
Also 60% of mac has virus, 80% of Windows has virus, 10% Linux has virus.
A random computer is chosen and is found to have virus. What is the probability that this computer is a Windows PC?
To a similar question my tutor recomended drawing up a table so I did that for this question as well but cant get the right answer.
| Virus | Non-Virus | TOTAL
Mac | 0.3*0.6= 0.18 | 0.3-0.18=0.12 | 0.3
Windows | 0.5*0.8= 0.4 | 0.5-0.4 =0.1 | 0.5
Linux | 0.2*0.1= 0.02 | 0.2-0.02 =0.18| 0.2
TOTAL | 0.6 | 0.4 | 1
I would have thought the answer is 0.4 but its 2/3 =S
Can someone please point out where iv gone wrong?
Sorry didnt know how to make a table and the extra spaces i tried to use dont seem to work...but you get the idea