In: Statistics and Probability
Marika wants to estimate how many coffees sold per week at the coffee shops and cafes in and around the University. She plans to do this by taking a sample of the coffee shops cafes and asking them how many coffees they have sold in the last week. There are 16 coffee shops and cafes (A to P).
Store |
Number of seats |
Number of coffees sold in week (yi) |
A |
8 |
455 |
B |
24 |
3512 |
C |
15 |
1129 |
D |
58 |
6424 |
E |
4 |
265 |
F |
90 |
8530 |
G |
31 |
3560 |
H |
11 |
567 |
I |
35 |
2633 |
J |
5 |
699 |
K |
14 |
756 |
L |
52 |
8267 |
M |
36 |
1742 |
N |
160 |
13440 |
O |
7 |
654 |
P |
5 |
656 |
Using number of seats as an auxiliary variable, describe how Marika could take a random sample of the coffee shops and cafes with replacement with the probability of selection proportional to number of seats. Marika can use pencil and paper or has basic skills with a spreadsheet, but does not know R.