Question

A student, by mistake, wrote 64 in place of 46 as a number at the time of finding the average of 10 given numbers & got the average as 50. The correct average of the numbers is

A) 48.2 B) 48 C) 48.1 D) 49

Answer 1

Sᴏʟᴜᴛɪᴏɴ :-

→ Total Number = 10

→ Average = 50

→ sum of all Numbers = (Total no. of observation ) * Average = 50 * 10 = 500 .

Now, we have given that, A student, by mistake, wrote 64 in place of 46 as a number.

we can say that, 500 is the sum with the wrong number 64 .

Now we have to remove 64 and put 46 to get our actual sum.

So,

→ Actual sum = 500 - 64 + 46

→ Actual sum = 500 - 18

→ Actual sum = 482

Therefore,

→ Actual sum = 482

→ No. of observations = 10

→ Correct Average = ( Sum of observation) / ( Total No. of observations) .

→ Correct Average = (482/10)

→ Correct Average = 48.2 (A) (Ans.)

Hence, The correct average of the numbers is 48.2 .