Question

The mean of 5 observations is 7. Later on, it was found that two observations 4 and 8 were wrongly taken instead of 5 and 9. Find the corrected mean.

Answer 1

Given: `N =5, barX=7`
`" "barX=(sumX)/N`
Or, `" "sum X=N xx barX`
`:." "sumX"(Wrong)" = 5 xx 7 = 35`
Correct `sumX = 35` + Correct items - Incorrect items
`" "=35+5+9-4-8=37`
Correct `barX=("Correct" sumX)/N= 37/5`
`= 7.4`
Thus, Corrected Mean = `7.4`.