Question

Mean of a – 2d, a – d, a + d and a + 2d is 

A) -a 

B) 3a 

C) a 

D) 5a

Answer 1

Correct option is: C) a

Mean = \(\frac {sum \, of \, observations}{Total \, number \, of\, observations}\) 

= \(\frac {(a-2d)+(a-d)+(a+d)+(a+2d)}{4} = \frac {4a}4 =a\)

Answer 2

Correct option is: C) a