Stratified Sampling

1)

Strata: Proportion Of Variability Of Data Gathering Cost

Retail Enviroment Type Customers Expenditure Per Respondent

Online Grocery Retailer 0.13 23 0.5

Supermarket 0.62 13 1

Small Grocer 0.11 4 2

Corner Shop 0.05 2 4.5

Daily Food Market 0.09 3 2

p x var p x var Ð'ЃÐ'Ђ Ð'ЃÐ"Јc

Online grocery retailer 2.99 4.23

Supermarket 8.06 8.06

Small grocer 0.44 0.31

Corner shop 0.1 0.05

Daily food market 0.27 0.19

Total 11.86 12.84

Sample of size 1300

Prop x 100 p x var Ð'ЃÐ'Ђ Ð'‡" p x var x 100 p x var Ð'ЃÐ'ЂÐ'ЃÐ"Јc Ð'ЃÐ'Ђ Ð'‡"p

x var Ð'ЃÐ'ЂÐ'ЃÐ"Јc x 100

Retail Enviroment type Proportional Optimal Disproportional

Online Grocery Retailer 169 328 427

Supermarket 806 883 817

Small Grocer 143 48 31

Corner Shop 65 11 5

Daily Food Market 117 30 20

2)