Intermediate Algebra: Connecting Concepts through Application

$4.75, 2.5, 0.25, -2, -4.25, -6.5, . . .$ $\frac{a_2}{a_1}=\frac{2.5}{4.75}=\frac{10}{19}=r$ $ra_2=\frac{10}{19}\times2.5=\frac{25}{19}\approx1.316\neq a_3$ and so the sequence is not geometric.