VCE General & Further Maths Question Thread!

[tannicholas]

This doesn't answer the question. The question implies that we should be checking if the doctor can conclude that none of the women they've tested has hypertension, not some purported entire population. There is no mention of a population. Good attempt though

I purposefully left my response open-ended because we'd like to see more working out appended to any question.

Since an answer has now been posted up, I may as well: the answer is no, you cannot conclude that none of the women has hypertension. A simple counterexample can be found by letting the blood pressure of three of the women be 139mmHg and the other be 141mmHg. The average is clearly below 140mmHg, yet one is above 140mmHg (implying that said woman has hypertension).

Hope this helps

right makes sense i thought this was a science prac question instead of a medical question.

[valjaybj]

hi if someone could help me with this q that'd be great

I thought the constraint would be 5x + 3y ≤ 15 but the solutions said 5x + 3y ≥ 15; why is the number of seats greater than or equal to 15? shouldn't it be less than or equal to 15 because the students cannot share a helicopter with anyone else?

[Commercekid2050]

Hi,

This is a good question. I could be wrong bit it could be including piolet as well which could make sense of why it being more than 15. The other reason could be that they are also including seats in the helicopter where no one is sitting. Which would mean more than 15 seats.

I hope this helps

[valjaybj]

Yeah ig the implication is that all 15 students are going on the helicopter so there's a minimum of 15 seats required ... a bit ambiguous though, anyways thanks!

[lm21074]

Yeah ig the implication is that all 15 students are going on the helicopter so there's a minimum of 15 seats required ... a bit ambiguous though, anyways thanks!

Yep, I don't think VCAA would be this ambiguous.

[tannicholas]

Does anyone know strategies about how to guarantee full marks on exam 2 without making careless mistakes?

[Chocolatepistachio]

for this question i don't get why this is the answer isn't it just 0.42 x 0.17. for independent events you x them and disjoint you add them

[Chocolatepistachio]

for this question int it just 0.69+ 0.4

[fun_jirachi]

for this question i don't get why this is the answer isn't it just 0.42 x 0.17. for independent events you x them and disjoint you add them

I'm not sure what you mean by the last part. This probably hints at a much larger gap in your understanding that we're missing. The solution is correct because when you want to find the probability of either event happening, you add the probability of each individual event, then subtract one instance of them both happening to account for double counting. Note that the last step doesn't exist for disjoint events since that is always 0 in that case.

As for why isn't it just 0.42 x 0.17; that's just because it's not intersection. Union implies an OR relationship, intersection implies an AND. Be careful when interpreting the question.

for this question int it just 0.69+ 0.4

How can it be 0.69+0.4? The probability of anything cannot exceed 1. This should already be ringing alarm bells in your head and telling you that you cannot possibly be correct. Again, reread the solutions which are correct; try to deduce how they step through it at the very least (it will help a little bit). Similar idea to the first question again here.

[lm21074]

Does anyone know strategies about how to guarantee full marks on exam 2 without making careless mistakes?

Unfortunately, there isn't really a way to guarantee full marks on exam 2 but I'd suggest checking your answers as you go and after you do them. By this, I mean check that you've entered numbers correctly into your CAS, the signs are correct on financial solver, you've put enough zeros in a calculation (I lost a mark on a SAC for writing 200 instead of 2000 - the epitome of careless mistakes ). If time permits, go through questions you found difficult first and then the rest of the questions.

Hope this helps

[Chocolatepistachio]

for this question ii
i don't understand why its 8.606 i thought it had to be less than 7.5358

[Chocolatepistachio]

i dont understand the answer for this question can someone explain and where did the 0.48 come from

[tannicholas]

Unfortunately, there isn't really a way to guarantee full marks on exam 2 but I'd suggest checking your answers as you go and after you do them. By this, I mean check that you've entered numbers correctly into your CAS, the signs are correct on financial solver, you've put enough zeros in a calculation (I lost a mark on a SAC for writing 200 instead of 2000 - the epitome of careless mistakes ). If time permits, go through questions you found difficult first and then the rest of the questions.

Hope this helps

thank you good news is that I haven't done some of these yet so there's still hope

[fun_jirachi]

for this question ii
i don't understand why its 8.606 i thought it had to be less than 7.5358

You've got it the wrong way around; the lower bound for a smaller confidence interval will be higher than the lower bound of a larger confidence interval. Intuitively, this is because more or less the larger confidence interval needs to encompass more numbers, so to speak.

i dont understand the answer for this question can someone explain and where did the 0.48 come from

I feel like there's missing context here. Not sure what p and q mean in this context.

Hope this helps

[tannicholas]

Can someone please solve this question and tell me what they got?