contestada

If the fifth term in a geometric sequence is 6 and the seventh term in the sequence is 96, what is the ratio (multiplier)?
A. 16
B. 8
C. 4
D. 6

Respuesta :

baabaagreysheep
Your answer would be C. 4
I'm sorry I got it wrong earlier, I'd delete this answer if I could, but read the other one for full details :)
apologiabiology
remember
in a geometric sequence
an=a1(r)^(n-1)
r=multiplier
a1=first term

given
a5=6 and
a7=96

a5=a1(r)^(5-1)=a1(r)^4
a7=a1(r)^(7-1)=a1(r)^6

a1(r)^4=6
a1(r)^6=96

if we divide them we get
96/6=(a1(r)^6)/(a1(r)^4)=
16=r^2 (remember, (r^6)/(r^4)=r^(6-4)=r^2)
sqrt both sides
4=r

the ratio is 4
C is answer