Answer:
It is a geometric sequence and the common scale factor is [tex]\frac{2}{3}[/tex].
Step-by-step explanation:
In an arithmetic sequence, the difference between consecutive terms is always the same.
[tex]a_n=a_1+(n-1)d[/tex]
where aₙ is the nth term, a₁ is the first term, n is the index, and d is the common difference.
In a geometric sequence, each consecutive term was multiplied by some factor over the last.
[tex]a_n=ax^n^-^1[/tex]
where aₙ is the nth term, n is the index, and x is the scale factor.
In the given sequence, there is no common difference so it is not an arithmetic sequence. There is, however, a common scale factor applied to each consecutive term. Each term is multiplied by [tex]\frac{2}{3}[/tex] over the last.
The formula for this sequence would be:
[tex]a_n=a\frac{2}{3} ^{n-1}[/tex]
Answer:
r = [tex]\frac{2}{3}[/tex]
Step-by-step explanation:
If the sequence is geometric then there will be a common ratio r between consecutive terms , that is
r = a₂ ÷ a₁ = a₃ ÷ a₂ = a₄ ÷ a₃
Then
a₂ ÷ a₁ = [tex]\frac{2}{9}[/tex] ÷ [tex]\frac{1}{3}[/tex] = [tex]\frac{2}{9}[/tex] × 3 = [tex]\frac{2}{3}[/tex]
a₃ ÷ a₂ = [tex]\frac{4}{27}[/tex] ÷ [tex]\frac{2}{9}[/tex] = [tex]\frac{4}{27}[/tex] × [tex]\frac{9}{2}[/tex] = [tex]\frac{2}{3}[/tex]
a₄ ÷ a₃ = [tex]\frac{8}{81}[/tex] ÷ [tex]\frac{4}{27}[/tex] = [tex]\frac{8}{81}[/tex] × [tex]\frac{27}{4}[/tex] = [tex]\frac{2}{3}[/tex]
Then sequence is geometric with common ratio r = [tex]\frac{2}{3}[/tex]
