Question

The ten test marks of two students are compared. Which student gets the more consistent mark? (calculate the standard deviation) Sue: 75, 59, 58, 72, 80, 66, 71, 79, 68, 55Leopold: 90, 83, 55, 84, 72, 63, 50, 65, 52, 91A: LeopoldB: Sue

Answer 1

Given..

Leopold: 90, 83, 55, 84, 72, 63, 50, 65, 52, 91

Sue: 75, 59, 58, 72, 80, 66, 71, 79, 68, 55

For Leopold:

`((90-70.5)^2+\cdots+(91-70.5))/(10)`
`(2230.5)/(10)=\sqrt[]{223.05}\text{ = }14.934858553063`

SD for Leopold = 14.934858553063

For Sue:

`((75-68.3)^2+\cdots+(55-68.3)^2)/(10)`
`(692.1)/(10)=\sqrt[]{69.21\text{ = }8.3192547743172}`

SD for Sue = 8.3192547743172

Option B or Sue is the answer