# Maths, Addmaths and Statistics: Post your doubts here!

#### vianrony

i need help in cosine rule

#### PlanetMaster

XPRS Administrator
i need help in cosine rule
Are you struggling to understand the rule or having issues applying it to questions?

#### badrobot14

XPRS Administrator
Are you struggling to understand the rule or having issues applying it to questions?
Having issues finding your reply between all the ads xD

#### ANaghAV

I have a doubt. How do you know when to use what in the Further Stat questions??? Esp. hypothesis-testing!

#### PlanetMaster

XPRS Administrator
Having issues finding your reply between all the ads xD
That was not in the options!

#### PlanetMaster

XPRS Administrator
I have a doubt. How do you know when to use what in the Further Stat questions??? Esp. hypothesis-testing!
Can you please provide an example question?

#### ANaghAV

Can you please provide an example question?
For example :

A college careers officer investigates the income at age 24 of a group of students who left school at 16, and a group who stayed on to take their A-Levels.
The results he finds are summarized in the table.
 16-year-old leavers A-Level leavers Mean 156 164 Sample estimate of variance 673 593 Sample size 37 28

Show, using a 2-sample t-test, that the hypothesis that those staying on at school have higher incomes at age 24 is rejected, on the evidence of this sample.

#### ANaghAV

For example :

A college careers officer investigates the income at age 24 of a group of students who left school at 16, and a group who stayed on to take their A-Levels.
The results he finds are summarized in the table.
 16-year-old leavers A-Level leavers Mean 156 164 Sample estimate of variance 673 593 Sample size 37 28
Show, using a 2-sample t-test, that the hypothesis that those staying on at school have higher incomes at age 24 is rejected, on the evidence of this sample.
can someone please help with this...?

#### PlanetMaster

XPRS Administrator
For example :

A college careers officer investigates the income at age 24 of a group of students who left school at 16, and a group who stayed on to take their A-Levels.
The results he finds are summarized in the table.
 16-year-old leavers A-Level leavers Mean 156 164 Sample estimate of variance 673 593 Sample size 37 28
Show, using a 2-sample t-test, that the hypothesis that those staying on at school have higher incomes at age 24 is rejected, on the evidence of this sample.
To test the hypothesis, we generally need to find the z-score also known as Test Statistic and then use it to find the p-value.
If $$p>0.05$$, this means that the mean values have no difference and the hypothesis is rejected.

Substituting your values in this online calculator, we get $$z=-1.275$$ and $$p=0.1036$$ and since $$p$$ is greater than $$0.05$$, we can say the hypothesis is rejected.

P.S. I am not 100% sure about this so please take this with a grain of salt.

#### ANaghAV

To test the hypothesis, we generally need to find the z-score also known as Test Statistic and then use it to find the p-value.
If $$p>0.05$$, this means that the mean values have no difference and the hypothesis is rejected.

Substituting your values in this online calculator, we get $$z=-1.275$$ and $$p=0.1036$$ and since $$p$$ is greater than $$0.05$$, we can say the hypothesis is rejected.

P.S. I am not 100% sure about this so please take this with a grain of salt.

Thank you soo much! That's exactly what the marking scheme says so you are perfectly correct! Cheers!

#### JesterDragon

How to revise maths for exams as someone who really hates maths and wants an A?

Practicing gets really boring for me. Most of the topics in my syllabus are ones I've done before, but need to (ugh)... practice.

It's too time consuming, and with other exams in the way, I have no idea how I'm going to cover the material. Any advice, guys?

#### kiran kk

How do I do this problem? Quite a challenge

#### Rashantha_W

Can anyone please upload pdf of these math books which are updated for the 2016 year onwards? Thankyouu

Cambridge O Level Mathematics Coursebook by Audrey Simpson

Cambridge O Level Mathematics

Heather West, Jean Matthews, John Jeskins, Mike Handbury
Did you find this ebook of Audrey Simpsons ? I also want the same !!

#### Loop man 123

Plz help Cambridge olevel Maths book by Aurdrey Simpson need plz

#### Dhammi

Can anyone please upload pdf of these math books which are updated for the 2016 year onwards? Thankyouu

Cambridge O Level Mathematics Coursebook by Audrey Simpson

Cambridge O Level Mathematics

Heather West, Jean Matthews, John Jeskins, Mike Handbury
hi, do any one have this book? I also need this. please help m.

#### friendlyguy

Dear ALL, Anybody has the pdf of " New Additional Mathematics ". Will appreciate it

#### Sabeen Naveed

Is the Casio fx-991ES PLUS calculator allowed in olevels Maths 4024? pretty sure it has some advanced features like doing metric conversions

#### AMOGUS

Hello does anyone have the answers of Complete Mathematics for Cambridge IGCSE fifthe Edition by David Rayner

Thanks in Advance

#### joe_mama

After the initiative taken by Math_angel in the IGCSE section, I have made this topic for students of O'levels. You can post any question or any problem here and me along with other XPF users will try to help you as soon as possible. This topic is a feasible option as it won't bring a hassle of making new topics for every question and it will also allow the helpers to not miss any of your questions and have one common topic for answering your Mathematics queries.

So start posting your problems.
Second year taking additional math, covered half the syllabus, asking for any important tips before the exam

#### HendraSu

Hi, everyone can any of you help me to find the softcopy of cambridge worked solutions manual for probability & statistics 1 ISBN-978-1-108-61309-5. and. Worked solutions manual for probability & statistics 2 ISBN-978-1-108-40734-2.
I need it to teach my son. Thank you in advance.

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