In an article, authors survey Black Friday shoppers. One question was "How many hours do you usually spend shopping on Black Friday?"
1. How many Black Friday shoppers should be included in a sample designed to estimate the average number of hours spent shopping on Black Friday if you want the estimate to deviate no more than 0.5 hour from the true mean?
2. Devise a sampling plan for collecting the data that will likely result in a representative sample.
1) The sample size of shoppers should be large. You need to get more variables to answer it precisely.
2) Sampling plan could be to go to the shops and check their billings on these days, you get to know how many customers visit the shops. Now you differentiate the shops on the basis of sales and then carry out the sampliing process.