AQA AS Mathematics MSB1 Statistics 1 – Wednesday 3rd June [Exam Discussion Thread]

*** This is a discussion thread for the June 2015 Statistics 1 Exam ***

Date: Wednesday 3^rd June
Time: 09:00
Duration: 1h 30m

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Resources

S1 Past Papers: goo.gl/uG6QZw

Summary Notes: goo.gl/1w5YX9

Revision Sheets: goo.gl/esddQw

Checklist: goo.gl/Dkq1SG

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(edited 8 years ago)

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Reply 1

jjsnyder

If anyone needs any help with S1 questions feel free to ask :smile:

Reply 2

jakecre8

Hey, how do you workout the interquartile range?

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Reply 3

Jimmy20002012

Original post by jakecre8

Hey, how do you workout the interquartile range?

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IQR: Q3-Q1.

Where Q3= 3n/4 and Q1= n/4, n= frequency.

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Reply 4

jakecre8

Thanks a lot jimjamjimmy

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Reply 5

dolphins321

When using the binomial distribution tables, how do you know what value of 'x' to use? (depending on whether the question is less than or equal to or something?)

Reply 6

Dieselblue

Original post by dolphins321

When using the binomial distribution tables, how do you know what value of 'x' to use? (depending on whether the question is less than or equal to or something?)

If you have P(X<200) or P(X>200) you use 200 as X for the equation in either senarios

Reply 7

cilla_e

When finding the median does it matter if you use,

n+1/2 or n/2

Reply 8

dolphins321

Original post by Dieselblue

If you have P(X<200) or P(X>200) you use 200 as X for the equation in either senarios

Is the number in the table for P(X<200)?

For P(X>200) would you do 1 - P(X<200)?

If it is equal to, don't you look at the row for 199 or something? This is where I get confused.

Reply 9

TheKian

How would I work out P(A|B)? I read that it was P(A and B) / P(A) or is it P(A or B)/P(A)

Reply 10

JellyCat99

Original post by TheKian

How would I work out P(A|B)? I read that it was P(A and B) / P(A) or is it P(A or B)/P(A)

I think the equation is in the formula book, it's P(A and B)/ P(B)

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Reply 11

jjsnyder

Original post by dolphins321

Is the number in the table for P(X<200)?

For P(X>200) would you do 1 - P(X<200)?

If it is equal to, don't you look at the row for 199 or something? This is where I get confused.

If it's equal to you can work it out P(X=<200) - P(X=<199)

Reply 12

jjsnyder

Original post by cilla_e

When finding the median does it matter if you use,

n+1/2 or n/2

You use (n+1)/2 when finding the median :smile:

Reply 13

Fudge2

Do we need to be able to find the exact value of the median from a grouped frequency table? Like I get how to find the class interval it's in but could we be asked to then work out its exact value? :smile:

Reply 14

jjsnyder

Original post by Fudge2

Yes you must be able to find the exact value for the estimation of the mean!
You can calculate it by Sum(fx)/Sum(f)

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Reply 15

Fudge2

Original post by jjsnyder

Yes you must be able to find the exact value for the estimation of the mean!
You can calculate it by Sum(fx)/Sum(f)

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Haha thanks but I was asking about the median :tongue:

Reply 16

Jimmy20002012

Can anyone help me on this question, have no idea.

ImageUploadedByStudent Room1432827114.004669.jpg

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Reply 17

Fudge2

Original post by Jimmy20002012

Can anyone help me on this question, have no idea.

ImageUploadedByStudent Room1432827114.004669.jpg

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I would guess 5 because all data in a normal distribution is contained within 2 SDs either side of the mean, so if all data is within 10g either side that suggests 10g is 2 SDs so 5g is 1 SD. That's the only thing I can think of because there's no data given...xD

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Reply 18

a123a

Original post by Fudge2

You would probably get a better estimate if you did 10/3 as then your using 3 S.Ds on either side of the mean. But your way still gets all of the marks!

Reply 19

Fudge2

Original post by a123a

You would probably get a better estimate if you did 10/3 as then your using 3 S.Ds on either side of the mean. But your way still gets all of the marks!

Ahh yeah cool that would be better. It's kinda a weird question imo cos the question could say that all of the data is within 100g either side which is still right and that would lead you to guess an sd of 50g..

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