Maths, Addmaths and Statistics: Post your doubts here!

vianrony · Oct 9, 2019

i need help in cosine rule

PlanetMaster · Oct 9, 2019

vianrony said:
i need help in cosine rule

Are you struggling to understand the rule or having issues applying it to questions?

badrobot14 · Oct 10, 2019

PlanetMaster said:
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 · Oct 10, 2019

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

PlanetMaster · Friday at 1:02 PM

badrobot14 said:
Having issues finding your reply between all the ads xD

That was not in the options!

PlanetMaster · Friday at 1:02 PM

ANaghAV said:
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 · Saturday at 4:34 AM

PlanetMaster said:
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 · Tuesday at 10:05 AM

ANaghAV said:
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 · Tuesday at 11:44 AM

ANaghAV said:
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 · Tuesday at 12:08 PM

PlanetMaster said:
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!