this involves arithmetic progression or you can have simple analysis
let 'x' be the first number
the difference is 4
the number of terms is 200
so you'll have:
[tex] A_{n} = A_{1} +(n-1)d[/tex]
[tex] A_{200} = x + (200-1)(4)[/tex]
[tex] A_{200} = x + 199(4)[/tex]
[tex] A_{200} = x + 796[/tex]
since we already have the last term then we may be able to find the difference between the first and the last term
[tex]difference = A_{200} - A_{1} [/tex]
[tex]difference = (x+796) - x[/tex]
= 796