Given the formula for the sequence:
[tex]S_n=4n^2+120[/tex]To find the 15th term, put n = 15 into the formula, that is:
[tex]\begin{gathered} S_{15}=4(15)^2+120 \\ S_n=4(225)+120 \\ =900+120 \\ =1020 \end{gathered}[/tex]Therefore, the statement given is true because the 15th term is indeed 1020
