VCE General & Further Maths Question Thread!

[Einstein]

hows this done

[Zealous]

hows this done

[Einstein]

sweet, thanks heaps!

did the scale factor of 1/2 come from 50/100?

thanks

[Einstein]

or was it, x for the bigger cone and 1/2x for the smaller one therefore scale factor 1/2

[2014year12]

Can someone please explain question 1. d)
I can't figure out how to get those answers?
I got the mean to be 4.4 and the standard deviation to be 3.9??
Thanks in advance!
(Picture attached)

[Aaron]

Can someone please explain question 1. d)
I can't figure out how to get those answers?
I got the mean to be 4.4 and the standard deviation to be 3.9??
Thanks in advance!
(Picture attached)

Can help in regards to the mean. You are not taking into account that these are intervals, not just values.

First, we need to get the mid-point of each interval.

Code: [Select]

Upper Bound = greater value of the range
Lower Bound = lower value of the range
(e.g. 100-200 where 200 is the upper bound, and 100 is the lower bound)



Now we find the frequency multiplied by the mid-point of each interval (this is required to calculate the mean soon)

Once you have done this, the mean is calculated like so:



I have attached a worked example of your question, in regards to this.

[jayzeek]

Hey guys! just found this forum on a whim and was wondering if anyone could help.

Was doing the 2013 geo module and am completely stumped by question 5.
http://imgur.com/yicZ8jO
Anyone mind walking me through it?

EDIT: Answer is C BTW!

[Conic]

4km is 4,000m, which is 400,000cm. So on the map the length is (400,000cm)/50,000=8cm.

[jayzeek]

4km is 4,000m, which is 400,000cm. So on the map the length is (400,000cm)/50,000=8cm.

Thanks, but I'm still a little puzzled, I believe I have been taught calculating contour map distance wrong because I was led to believe you just simply times the distance by the number to the right in the scale. So what I was doing was

50,000 x 4 = 200,000
200,000 / 100,000 (convert into cm from km)
= 2cm

Clearly this is wrong, should I be employing a formula that uses ratios?

[Conic]

I would use ratios because they give it to you as a ratio. They give you the ratio as 1:50,000. This means that distances in real life are 50,000 times greater than on the map. So to scale real world distances down we need to divide by 50,000, because we know they are 50,000 times greater than they are on the map. So the 400,000cm real world distance becomes 8cm on the map.

"50,000 x 4 = 200,000
200,000 / 100,000 (convert into cm from km)
= 2cm"

In your first step you are scaling a number in km upwards, so the result should be in km. In your second step you are dividing a number in km to convert to cm, but the number in cm should be larger, as you can fit a lot of cm in a km. It is probably easier and more accurate to break it down and do it step by step than by using a formula.

[jayzeek]

Okay that does clear things up, thank you!

[darklight]

Couldn't the answer be either D or E considering they are interchangeable?

[Einstein]

how is Q9 drawn? i know the math, but when i drew it and tried to figure it out it didnt get the answer.

with Q13, how do i do it?

thanks

[Einstein]

another few questions, im stuck on how i do question 14 and 15.

thanks

[~V]

how is Q9 drawn? i know the math, but when i drew it and tried to figure it out it didnt get the answer.

with Q13, how do i do it?

thanks

The diagram for 9 even though it's a bit dodgy.
Also, i think for question 15, from the top of my head it's using either the sine or cosine rule. I think you have 3 angles and a side (30cm) 105, 37.5, 37.5 (??). Im not up to the trigonometry module just yet and this is all the things i remember last year, so i might be wrong.