In a city, all 10,000 households are classified into three strata according to the income of

households (low / medium / high).We draw a stratified sample of 400 households for which we

observes the variabley, defined as the value of food expenditure for householdi.here are the

Sample size 400 is a preliminary sample intended to prepare for a new sample

stratified, larger, size 2000. Determine the number of households to be sampled in stratum 1

according to the optimal allocation of a sample of size 2000. Note: use the corrected standard deviation of

sample income.

Stratum 1 N = 5000; n = 200; = $ 240;} = $ 30 Households with low income Stratum 2 N = 2500; n = 100; = $ 380;y s = $ 50 2 Households with an average income Stratum 3 N = 2500; n = 100; = $ 750; y = $ 90 3 Households with high income