Question

the mean of four observation​ is 10 ,and a constan a is added to each observation , the mean becomes 13. the value of a is​

Answer 1

Answer:

Let the four observations be p. q, r, s

Mean =(p+q+r+s) /4=10

p+q+r+s=40

[P+a)+(q+a)+(r+a)+(s+a)]/4=13

40+4a=52

a=3