Question

Find the three arithmetic means between 7 and 21.

Answer 1

arithmetic mean of 7 , 21
(7 + 21) /2   = 14

Arithmetic mean of 7 and 14
(7+ 14) /2   = 10.5

Arithmetic mean of 14 and 21
(21 + 14)/2 =17.5

so, the three arithmetic means would be : 10.5 , 14 , and 17.5

hope this helps