Question

380 students in key stage 3. 240 students in key stage 4. 110 students in key stage 5. She needs a sample of 100 students stratified by key stage. Work out the number of students from key stage 3

Answer 1

52

Explanation:

Number of Students in Key Stage 3 =380

Number of Students in Key Stage 4 =240

Number of Students in Key Stage 5 =110

Total = 380+240+110=730

Since a sample of 100 students stratified by key stage is needed.

The number of students that would be taken from Key Stage 3

`=(380)/(730)* 100\\\\=52.1\\\approx 52 $ (to the nearest whole number)`