#### vianrony

i need help in cosine rule

#### PlanetMaster

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

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

Having issues finding your reply between all the ads xD That was not in the options! • #### PlanetMaster

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.

#### PlanetMaster

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.

• ANaghAV

#### 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.

• 