Question

the average weight of 9 boys in a class is 42 kg another ball jointed the class and new average was found to be 42.5 kg find the weight of new boy​

Answer 1

Answer:

47kgs

Step-by-step explanation:

AVERAGE= SUM OF OBSERVATION/ NO. OF OBSERVATIONS

the average weight of 9 boys in a class= 42kgs

The sum of  weight of 9 boys= 42 X 9= 378kgs

After the addition of 1 more boy (new total no. of boys= 10),

the new average= 42.5kgs

new sum of weight of boys= 42.5 X 10= 425kgs

weight of the new boy= new weight of boys- previous weight of boys

                                  = 425- 378

                                  =47kgs

therefore the weight of the new boy is 47kgs