Given Are the First Three Terms of a Sequence That $\frac { 3 } { 4 } , \frac { 3 } { 16 } , \frac { 3 } { 64 } , \ldots$

Multiple Choice

Given are the first three terms of a sequence that is either arithmetic or geometric. If the sequence is arithmetic, find a1
and d. If a sequence is geometric, find a1 and r.
- $\frac { 3 } { 4 } , \frac { 3 } { 16 } , \frac { 3 } { 64 } , \ldots$

A) $a _ { 1 } = \frac { 3 } { 4 } , r = 4$
B) $a _ { 1 } = \frac { 3 } { 4 } , r = 40$
C) $\mathrm { a } _ { 1 } = \frac { 3 } { 4 } , \mathrm { r } = \frac { 1 } { 40 }$
D) $\mathrm { a } _ { 1 } = \frac { 3 } { 4 } , \mathrm { r } = \frac { 1 } { 4 }$