Question

7.
"The average weight of 5 persons is 61 kg. If each person reduces their
weight by 2 kg, then their average weight will be 59 kg." Is it true ? Justify.​

Answer 1

Step-by-step explanation:

61×5=305

305-5*2=305-10=295

295/5=59

Answer 2

Answer:

True.

Step-by-step explanation:

If all observations change ( after adding subtracting or dividing ) by some factor then their average will also change by the same factor,

For example :

Let $x_1, x_2, x_3, x_4$ are observations,

Their average = $\frac{x_1+x_2+x_3+x_4}{4}$

If new observations are,

$x_1+a, x_2+a, x_3+a, x_4+a$

New average = $\frac{x_1+x_2+x_3+x_4+4a}{4}$

$=\frac{x_1+x_2+x_3+x_4}{4}+a$

= Original average + a,

Hence, if the average weight of 5 person is 61 kg,

Also, If each person reduces their  weight by 2 kg then their average will reduce by 2 kg,

i.e. new average weight = 61 - 2 = 59 kg