Question

The average height of 25 boys was calculated to be 200 cm. It was detected later that one value of  169 cm was wrongly copied as 144 cm for the computation of the average. Find the correct average.

1. 213
2. 206
3. 200
4. 201
5. None of these

Answer 1

Correct Answer - Option 4 : 201

Given

average height of 25 boys = 200 cm

Formula Used 

Average = Sum of observation/No. of observation

Calculation

Incorrect sum of the heights of 25 boys = 200 × 25 = 5000 cm

Now,

Correct sum of the heights of 25 boys = (incorrect sum) – (wrongly copied value) + ( actual value)

⇒ (5000 – 144 + 169) cm = 5025 cm

So, the correct average = correct sum / number of boys

⇒ 5025 / 25 = 201 cm

∴  The correct average height is 201.