Question

The average of first 30 natural numbers is (a) 30.5 (b) 60.5 (c) 15.5 (d) 16.2​

Answer 1

Answer:

(c)15.5

✿ ✿step by step explanation✿ ✿

average=sum of observations/number of observations

=1+2+3+4+5+6+7+8+9------+30/30 ...(1)

now sum of observations can be found with the help of arithmetic progression (AP)

a=1

n=30

d=1

Sn=n/2{2a+(n-1)d}

=30/2{2*1+(30-1)1}

=15{2+29}

=15*31

=465

put this value in equation (1):

=465/30

=15.5