Help with a question

• Nov 23rd 2007, 09:04 AM
leaaa
Help with a question
Hi,

I have a workbook of questions, this doesnt have to be handed in, im just using it for revision, but it has no answers, so that doesnt help when i have no idea where to start or what type of question it is!!

So here it is feel free to help me lol

Twenty students were asked to fill in a questionnaire about their spending habits. The results are attached on a data sheet where 0 indicates males and 1 indicates female under Sex.
Under employment 0 indicates working and 0 indicates not working under Employment; and age is in years.

http://i18.photobucket.com/albums/b1...annx/maths.png

The Mean is £15.30

A) Calculate the amount spent on alcoholic drink using standard deviation.
• Nov 24th 2007, 01:06 AM
CaptainBlack
Quote:

Originally Posted by leaaa
Hi,

I have a workbook of questions, this doesnt have to be handed in, im just using it for revision, but it has no answers, so that doesnt help when i have no idea where to start or what type of question it is!!

So here it is feel free to help me lol

Twenty students were asked to fill in a questionnaire about their spending habits. The results are attached on a data sheet where 0 indicates males and 1 indicates female under Sex.
Under employment 0 indicates working and 0 indicates not working under Employment; and age is in years.

The Mean is £15.30

A) Calculate the amount spent on alcoholic drink using standard deviation.

As stated this does mot make sense. Now if it asked you to calculate the
mean and standard deviation of the amount spent on drink that would be
a question. You might also be asked to claculate the mean and standard deviation of the amount spent by males or females, ....

The formula to use to calculate the mean and standard deviation are:

$m=\frac{\sum_{i=1}^n x_i}{n}$

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-m)^2}{n}}$

where $\sum_{i=1}^n$ means we sum the terms following with n index of summation $i$ runs from $1$ to $n$ where each $i$ corresponds to a different case in the sample.

RonL