geometric sequence
\(a_n=a1r^{n-1}\)
r=common ratio
a1=first term
n=which term
2nd term is 50
4th is 112.5
\(a_2=a1r^{2-1}\)=50
\(a_2=a1r^{4-1}\)=112.5
50=\(a1r^{1}\)
112.5=\(a1r^{3}\)
therefor
112.5/50=\(\frac{a1r^3}{ar^1} =r^2\)=2.25
r^2=2.25
sqrt both sides
r=1.5
the common ratio is 1.5
