Question

2018 Q1:

A cafe on campus serves coffee and tea. They are considering selling cold drinks as well (e.g. fruit juices, smoothies) to get more customers. Since they want to find out what kind of drink appeals to what kind of customer, they plan to sample current customers. You have been employed to create their survey design. The cafe is open from 7am to 7pm Monday to Friday and they have about 5000 customers a day. They sell light snacks (e.g. muffins and sandwiches) as well, but not restaurant-style food.

(a) What sample design would you recommend (e.g. simple random sampling or systematic sampling, or stratified sampling, or cluster sampling, or pps sampling, or adaptive sampling, or some combination)? Clearly explain why you chose this design, including any assumptions you have made. You may want to consider part (b) of this question when choosing your design.

(b) The people in the cafe will be running the survey and have no statistical or mathematical background and will be still expected to serve customers. Write the instructions for them on how they are to select their sample given your proposed design from part (a). Assume they can spend no more than 10 hours during the week collecting the data.

(c) Describe 3 possible sources of non-sampling error in the survey.

(d) Describe how the data they collect may not be informative for their purpose of deciding whether selling cold drinks will increase business.

Answer 1

thank you