http://www.gcseguide.co.uk/standard_deviation.htm

The definitions for mean, mode and median are in the glossary of your textbook. You need to understand all three to offer your opinion as to which is best for your 50 student group.

You must have also had discussion or papers about an obesity awareness campaign. Review thtat, and decide which are the best things you could do to draw attention to fat as a health issue, IN A POSITIVE fashion 🙂

Good luck.

For the last formula, check out the cover of your calculator. ( Casio fx-350ms) Follow the steps and you should get the answer.

For the best measure of central tendency, check out the text book for explanations.

The role, however, is rather complicated. Its like writing an essay more than doing maths. My personal idea:

1) exercise healthy eating habits

2) educate others in evaluating healthy eating habits

3) take part in exercise programs

4) get rid of unhealthy habits (smoking, overeat, etc.)

For the roles, select only the ones that is/are appropriate.