How would you answer this question?

: I am running a survey for my dissertation in gym %26amp; I need to hand this questions with the questionnaire I am going to run.





How many people should Interview if the gyms has 5.000 members and 800 people come through the doors everyday?





Approximately how many participants are to be recruited, how will they be selected, and how will they be invited to participate in the study.


how could I answer that?


thanks

How would you answer this question?
I'd probably run two surveys: a postal random-sample survey and a separate quota sample of in-depth face to face interviews.


Survey 1: A 10% random sample of the total membership - 10% is more than adequate but if you can afford to mail 20% it should mean that your response will be better (in total numbers replying). This type of survey requires you to , mail questionnaires to 500 (10%) members, selected randomly from the membership list by starting at a random number between 1 and 10, (e.g. 7 and taking every membership number ending in 7). It's unlikely that you'd get a 100% response, or even 50%, but that doesn't matter - whatever response you get you can test the confidence limits using the stats that you've learnt and incorporate that in your analysis of the results that you get.


Survey 2 is a little bit more tricky. This is a QUOTA sample of actual users. You should look at the membership data (all 5000 members) and try to construct a table that shows how many males and females you have in each of the age groups 21-30, 31-40, 41-50 and so on. You should then aim to get interviews with a balanced number of members reflecting the sex and age profiles of the membership. Since you will be doing a face-to-face interview with each member who fits one or other of the profiles, you need to have a set of standard questions to ask. What these are depends on what you want to find out.


If 800 people come through the doors each day, this suggests that the gym is quite successful at what it does. 800 members is 16% of the total. If you can interview 1 in 4, that will give you 100 quota sample interviews. That's plenty. You should get some good results.


Don't forget to interview the Centre manager and one or two of the trainers and recruiters, to get a balanced oicture of how the centre operates - this will help to give your survey a high level of usefulness.
Reply:You should intrview all the 5000 members whether that be through the post or on phone to recommend their family and friends etc x