Question 800372
its arithmetic progression

The nth term is given by
Tn = a+(n-1)d

a= first term
d= difference between terms
n = number of terms

208=4+(n-1)4

208=4+4n-4
208=4n
n=52

Sum of n terms 
Sn = n/2(2a+(n-1)d)

Sn = 52/2(2*4+(51*4)

=27(8+204)
=27*212
=5724

208=4(n-1)4