Answer:
7, 10 and 13.
Step-by-step explanation:
If there are 3 means between 4 and 16 then:
16 is obtained by adding the common difference 4 times:
(16 - 4)/4 = 12/4 = 3 = common difference.
So the 3 arithmetic means are 4+3, 4 +2*3, 4 + 3(3)
That is 7, 10 and 13.