I hope these videos solutions are helpful. The solutions have been split into two videos this year to be a little more helpful. Let me know what you think of them by leaving me a comment. Head to www.maffsguru.com for more video resources.
You need to put the following into your Financial solver: N: 3*12 (as there are 12 monthly payment over three years) I: 4.1 (given in the question) PV: 329 587.25 (we can pretend this was the amount given by the bank) PMT: Trying to find it FV: -280 875.15 (the value after seven years) PPY: 12 CPY: 12 The trick here is to realise that a Principal Value doesn't have to be at the start of the loan. We can use it at any point. So, in this case, we thought of the start of the third year as my PV and then my FV was what I had at the end of the seventh year. I hope this helps and answers your question! Wishing you the very best of luck in your exams.
Hi! great explanations thankyou. just wanted to clarify how u got 171 for the intercept on question 6c. what other values did you use in the straight line equation?
I always use the equation y-y1=m(x-x1). So using the point (20, 168) I made y1=168, x1=20 and I worked out the value of m to be -11/65 ... when I put these into the CAS, it gave me the intercept as 171. I hope this answers your question.
How do we know though the association is strong tho? it could have moderate if they decided to trick us. and in question6d how do we know which transformation to do? cheers
The association is strong because the dots are pretty close to the line. Normally we would get the answer from the value of 'r' but here they wanted to see if you understood that 'r' was. You were told to apply the transformation to the mean age (which is on the 'x' axis). Using the circle of transformations I had a choice (for the data I was given) to transform either x^2 or y^2. As I had to transform the x-axis, I had to use the x^2 transform. I hope this helped!
@@MaffsGuru thank you very much and one more qn if thats alright, in qn bii at 5:48 could you please go into more depth as this question seems very confusing and i can figure out how to use the actual data.
OK! I'll do my best. You needed to use the values for the mean and standard deviation to find the limits of what 3 standard deviations above and below the mean were. Hence mean was 38 and standard deviation was 2.3. I did 38 + (2.3 * 3) and 38 - (2.3 * 3) which gave me the limits of the values i was looking for. I then looked at the actual data and as the third standard deviation below the mean was 31.1, there was one point to the left of this i.e. more than 3 standard deviations. When I looked at the third standard deviation above the mean of 44.9, there were no actual points above that line ... hence the answer turned out to be 1. Did that makes sense?
As we are predicting "body density" from "weight" this tells you that the body density goes on the y axis and the weight goes on the x-axis. What you predict always goes on the y-axis. I hope this helps!
Hi. I used the recurrence relationship on my CAS and, with a starting value of 5000, kept multiplying my answers by 1.003 and then adding 50. This, after 12 times, gives 5793. I hope this answers the question. Sorry for the late reply. I only just saw this comment
@@bianca-n81 You might be able to use the finance solver, but the keystrokes needed for that would be more or the same for just hitting enter 12 times.
That last question stumped me lol I think I understand it now tho! And I didn't make any other mistakes, which was nice :) Hopefully I do as well on Monday...
Well done! The last question of which section stumped you??? Fingers crossed that you do brilliantly on Monday!!!! Let me know if there is anything I can do to help
For question 2c in the data section, the question didn't ask for rounding. Why did you round? I was taught to round when the question asks you to so I'm a bit confused.
Hi Hinal. I got a different upper and lower fence to what you quote in your question. I got 31.5 and 43.5 which is why I I made the lines as long as I did . I hope this answers your question.
you had to round 0.75 to the nearest whole number as the question was asking about people and obviously you can't have a 0.75 of a person so the answer had to be 1
I hope these videos solutions are helpful. The solutions have been split into two videos this year to be a little more helpful. Let me know what you think of them by leaving me a comment. Head to www.maffsguru.com for more video resources.
just a qs but why did u extend the whisker to 32 and 43 when the upper and lower fence was 31.5 and 44.5 for qs 2 d?
can you pls explain last question (q11) and how you got $2400 as your monthly repayment
You need to put the following into your Financial solver:
N: 3*12 (as there are 12 monthly payment over three years)
I: 4.1 (given in the question)
PV: 329 587.25 (we can pretend this was the amount given by the bank)
PMT: Trying to find it
FV: -280 875.15 (the value after seven years)
PPY: 12
CPY: 12
The trick here is to realise that a Principal Value doesn't have to be at the start of the loan. We can use it at any point. So, in this case, we thought of the start of the third year as my PV and then my FV was what I had at the end of the seventh year.
I hope this helps and answers your question!
Wishing you the very best of luck in your exams.
Hi! great explanations thankyou. just wanted to clarify how u got 171 for the intercept on question 6c. what other values did you use in the straight line equation?
I always use the equation y-y1=m(x-x1). So using the point (20, 168) I made y1=168, x1=20 and I worked out the value of m to be -11/65 ... when I put these into the CAS, it gave me the intercept as 171. I hope this answers your question.
great job of explaining
Thanks so much for taking the time in leaving me such a great comment. I was worried that there wasn't enough explanation.
Can you pls explain the last question how did you get $2400 as monthly payment??
Hi Parmida. Are we talking about the last question of the financial section?
yes pls I didn't understand how you done the last question too@@MaffsGuru
How do we know though the association is strong tho? it could have moderate if they decided to trick us. and in question6d how do we know which transformation to do? cheers
The association is strong because the dots are pretty close to the line. Normally we would get the answer from the value of 'r' but here they wanted to see if you understood that 'r' was. You were told to apply the transformation to the mean age (which is on the 'x' axis). Using the circle of transformations I had a choice (for the data I was given) to transform either x^2 or y^2. As I had to transform the x-axis, I had to use the x^2 transform. I hope this helped!
@@MaffsGuru thank you very much and one more qn if thats alright, in qn bii at 5:48 could you please go into more depth as this question seems very confusing and i can figure out how to use the actual data.
OK! I'll do my best. You needed to use the values for the mean and standard deviation to find the limits of what 3 standard deviations above and below the mean were. Hence mean was 38 and standard deviation was 2.3. I did 38 + (2.3 * 3) and 38 - (2.3 * 3) which gave me the limits of the values i was looking for. I then looked at the actual data and as the third standard deviation below the mean was 31.1, there was one point to the left of this i.e. more than 3 standard deviations. When I looked at the third standard deviation above the mean of 44.9, there were no actual points above that line ... hence the answer turned out to be 1. Did that makes sense?
what do we input on the x and y axis for question 4b iii, cuz my cas has a diferent r value
As we are predicting "body density" from "weight" this tells you that the body density goes on the y axis and the weight goes on the x-axis. What you predict always goes on the y-axis. I hope this helps!
hi for q9c finance how did you get 5793
Hi. I used the recurrence relationship on my CAS and, with a starting value of 5000, kept multiplying my answers by 1.003 and then adding 50. This, after 12 times, gives 5793. I hope this answers the question. Sorry for the late reply. I only just saw this comment
@@MaffsGuru is there a faster way to do this than put it in the calculator 12 times ?
@@bianca-n81 You might be able to use the finance solver, but the keystrokes needed for that would be more or the same for just hitting enter 12 times.
That last question stumped me lol I think I understand it now tho! And I didn't make any other mistakes, which was nice :) Hopefully I do as well on Monday...
Well done! The last question of which section stumped you??? Fingers crossed that you do brilliantly on Monday!!!! Let me know if there is anything I can do to help
For question 2c in the data section, the question didn't ask for rounding. Why did you round? I was taught to round when the question asks you to so I'm a bit confused.
Can I just clarify that you meant 2c? This seems to be asking for a box plot.
@@MaffsGuru Never mind sorry. I noticed you said lowest data item which is 32. I thought you just rounded it up to 32 from 31.5 as the lower fence.
Phew! I was worried there for a moment!!!
@maffsguru just a qs but why did u extend the whisker to 32 and 43 when the upper and lower fence was 31.5 and 44.5 for qs 2 d?
Hi Hinal. I got a different upper and lower fence to what you quote in your question. I got 31.5 and 43.5 which is why I I made the lines as long as I did . I hope this answers your question.
i got 0.75 for question 2 b, how did you get 1
round up
Which module are we looking at?
you had to round 0.75 to the nearest whole number as the question was asking about people and obviously you can't have a 0.75 of a person so the answer had to be 1
@@jordanmunn1855 thanks for replying. Really appreciate it.