Question

The average weight of a group of 20 boys was calculated to be 89.4 kg.it was later discovered that one weight was misread as 78kg.instead of 87kg.the correct average weight is?

Answer 1

Correct Answer is: 89.85 KgExplanation:Total weight = 89.4 x 20 = 1788 kgCorrect total weight = 1788 – 78 + 87 = 1797Correct Average = 1797 / 20 = 89.85 kg 

Answer 2

Answer:

The correct average weight is 89.85 Kg

Step-by-step explanation:

Given that the average weight of a group of 20 boys = 89.4 kg

Sum of a weight of 20 boys = 89.4 × 20

                                               = 1788 kg  

It was later discovered that one weight was misread as 78 kg instead of 87 kg

⇒  Difference between the misread weights = 87 - 78

                                                                         = 9 kg

So, Actual sum of a weight of 20 boys = 1788 + 9 = 1797 kg

$\implies \textbf{Actual Average = }\bf \frac{1797}{20}\approx 89.85\:\:Kg$

Therefore, The correct average weight is 89.85 Kg