Answer:
21, 27, 33, 39, 45
Step-by-step explanation:
let find the difference to get the three arithmetic means
a = 21
5th term = 45
AP = a + (n - 1)d
45 = 21 + (5 - 1 )d
45 = 21 + 4d
45 - 21 = 4d
4d = 24
divide both sides by 4
d = 24/4
d = 6
Find the 2nd, 3rd and 4th term
a + d
2nd term = 21 + 6 = 27
3rd term = 27 + 6 = 33
4th term = 33 + 6 = 39
