- A local authority official wishes to conduct a survey of households in the borough. He decides to select a stratified sample of 2000 households using Council Tax property bands as the strata. At the time of the survey there are 79368 households in the borough. The table shows the numbers of households in the different tax bands.
| Tax band | A-B | C-D | E-F | G-H |
| Number of households | 32298 | 33211 | 9739 | 4120 |
a. Calculate the number of households that the official should choose from each stratum in order to obtain his sample of 2000 households so that each stratum is represented proportionally.
b. State one advantage of stratified sampling over simple random sampling.