Conditional Probability 6 • Exam Questions pt. 2 • Stats2 Ex2 ExamQ • 🚀

[@benlynch7812]

Thank you so much for this!

[@Ahmed-ft3gp]

honestly brilliant video, as always.

[@qafrd5487]

Sir, if 2 events are independent, does that mean the 2 events not happening are also independent?

[@BicenMaths]

Yes!

[@qafrd5487]

@@BicenMaths alright, thanks!

[@nullgravity2583]

Thanks. My IAL stats exam is tmrw

[@BicenMaths]

How did it go?

[@mattp9445]

As an alternative to part c on the last question, Could you say that from the independence law, that P(A' n B') = P(A') × P(B') Essentially, taking the complement and treating them as 2 new independent events then using the independence law on these new events. Or is that incorrect? If it is correct, then that would seem to be an easier way of answering the question but completely different to the markscheme.

[@BicenMaths]

Probability isn’t my specialty area, but I think your logic is true. If A and B are independent, then so should A’ and B’, so you could show that using your explanation. Interesting approach!

[@gunjitaswami7743]

for 11:24 how did you infer the given that part?

[@lotsoflove6182]

because the question says "a machine is randomly selected and it has tested positive for a fault" so it's given that it has tested positive for a fault

[@gunjitaswami7743]

@@lotsoflove6182 thanksss

[@lizzie12362]

For stratified sampling, if the answer is a decimal, do we round up or down?

[@BicenMaths]

I would round to the nearest integer - just be careful that this sometimes leads to the total not quite adding up, so you may need to adjust one of them at the end so it adds up correctly! Just change the one that was closer to .5

[@lizzie12362]

@@BicenMaths Alright sir, thank you.

[@aaronennis1195]

for part c I got 0.1925 than added everything up to see if I would get 1

[@nullgravity2583]

That's a good way of verifying your work, but not necessary