Question 1204307


geometric sequence {{{n}}}th term formula is:

{{{ a[n]=a[1]*r^(n-1)}}}


given:

{{{ a[1]=0.3}}}

{{{ a[8]=83.4}}}

plug it in formula above an solve for {{{r}}}

{{{ 83.4=0.3*r^(8-1)}}}

{{{ 83.4=0.3*r^7}}}

{{{ r^7=83.4/0.3}}}

{{{ r^7=278}}}

{{{ r=root(7,278)}}} => exact solution, your answer


and, your formula is:

{{{ a[n]=0.3*(root(7,278))^(n-1)}}}