Question:
What is the common ratio between successive terms in the sequence?
27, 9, 3, 1
Answer:
common ratio = [tex]\frac{1}{3}[/tex]
Step-by-step explanation:
In a geometric progression, the common ratio, r, is the ratio of a term in the sequence to a preceding term in that same sequence. In other words, the common ratio is found by dividing a term by the term just before it. For example, if the geometric sequence is:
a, b, c, d...
The common ratio is found by any of the following;
r = [tex]\frac{b}{a}[/tex] ----------(i)
r = [tex]\frac{c}{b}[/tex] -----------(ii)
r = [tex]\frac{d}{c}[/tex] ------------(iii)
Any of equations (i) through (iii) will give the common ratio of the sequence.
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Now, from the question, the given sequence is;
27, 9, 3, 1
To get the common ratio, just divide the second term (9) by the first term (27) i.e
r = [tex]\frac{9}{27}[/tex] = [tex]\frac{1}{3}[/tex]
OR
You can also divide the third term (3) by the second term (9). i.e
r = [tex]\frac{3}{9}[/tex] = [tex]\frac{1}{3}[/tex]
OR
You can choose to divide the fourth term (1) by the third term (3). i.e
r = [tex]\frac{1}{3}[/tex]
Which ever adjacent terms you choose gives you the same result. Therefore, the common ratio of the given sequence is [tex]\frac{1}{3}[/tex]