Help with s1 may 2013 (r)

So this is the weird paper Edexcel S1 May 2013 (R) and it's question 3(e) that I don't understand....I guessed that it was 12 tomato plants but I don't understand how you work it out...please help!

(edited 9 years ago)

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Reply 1

Puddles the Monkey

Original post by lightningdoritos

So this is the weird paper Edexcel S1 May 2013 (R) and it's question 3(e) that I don't understand....I guessed that it was 12 tomato plants but I don't understand how you work it out...please help!

Heya, I'm going to put this in the Maths forum for you as you should get more responses there. :smile:

You should also check out the forum to see if there's any other threads there which might be helpful to you! http://www.thestudentroom.co.uk/forumdisplay.php?f=38

Reply 2

davros

Original post by lightningdoritos

So this is the weird paper Edexcel S1 May 2013 (R) and it's question 3(e) that I don't understand....I guessed that it was 12 tomato plants but I don't understand how you work it out...please help!

You really need to post the actual question, otherwise most people aren't going to have a clue what this is about!

Reply 3

username1226161

Original post by davros

You really need to post the actual question, otherwise most people aren't going to have a clue what this is about!

Ah okay sorry will do :smile:

Reply 4

studentwiz

Original post by lightningdoritos

Ah okay sorry will do :smile:

I don't get it did you manage to get an answer?

Reply 5

username1226161

Original post by studentwiz

I don't get it did you manage to get an answer?

At first I just guessed and got the right answer but then I used a histogram although that's not how you're 'supposed' to do it apparently? So basically I drew the histogram for the last three groups and worked out frequency density for each. Then I "cut" the 15-25 bar down into two parts (due to the mean+1 standard deviation equalling 18.3 or something). Then I worked out the area of the 18.3-25 'half' bar which was the frequency and added it on to the four in the last group.

Hope that made sense!

Reply 6

studentwiz

Original post by lightningdoritos

that's mad confusing, its fine tho. Have you done question 5d and e if so could explain that I feel those are some easy marks.

and question 7g I don't get that one

Reply 7

username1226161

Original post by studentwiz

that's mad confusing, its fine tho. Have you done question 5d and e if so could explain that I feel those are some easy marks.

and question 7g I don't get that one

Yeah I know.....only two marks as well! :frown:

Sorry but I haven't done those ones...I'm doing a Maths Tallis paper so it's not really a full paper, just random questions...but I'll try and find out when I do it!

Reply 8

Gome44

Add the mean to the standard deviation. You should get 18.2444..... Now anything above this value is what you want, so you can use interpolation reversed to estimate what frequency this occurs at. Then do 70-that frequency, and you should get the required answer

Reply 9

studentwiz

Original post by Gome44

use interpolation on what? the mean??

Reply 10

Gome44

Original post by studentwiz

use interpolation on what? the mean??

Interpolation is estimating the value of something in grouped data if you know the frequency. This time, you know the value in the grouped data (18.244....), which is the mean + 1sd, so you can work backwards to find out what frequency this occurs at

Reply 11

studentwiz

Original post by Gome44

yes but how do you use interpolation in this case?

Reply 12

Super199

I hate bloody questions like these :frown:

Reply 13

Gome44

ImageUploadedByStudent Room1401810811.340002.jpg

ImageUploadedByStudent Room1401810834.060328.jpg

Original post by studentwiz

yes but how do you use interpolation in this case?

Reply 14

studentwiz

Original post by Gome44

I followed all the way till tposition -54 why minus 54?

Reply 15

Gome44

That's the cumulative frequency upto the class 15<y<25

I have written the formula for interpolation on the sheet. The formula is just a general rearrangement of the ratio method in the textbook

(edited 9 years ago)

Reply 16

Whizzkid03

Original post by username1226161

So this is the weird paper Edexcel S1 May 2013 (R) and it's question 3(e) that I don't understand....I guessed that it was 12 tomato plants but I don't understand how you work it out...please help!

Hi I’m currently doing older past paper questions and I was also stuck on how to do this,thanks for putting it on student room.I hope all the best for u :smile: