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Find the common ratio before trying to calculate the geometric means.
24, 72, 216 or - 24, 72, - 216
We want to find the geometric means in the given sequence. To do so, we first have to find the value of the common ratio r.
8, , , , 648
From the sequence, we know the value of the first term and that there are 5 total terms. We can substitute 8 for a_1 and 5 for n in the general formula for the nth term of a geometric sequence.
a_5= 648
Subtract term
.LHS /8.=.RHS /8.
sqrt(LHS)=sqrt(RHS)
Calculate root
Rearrange equation
We found that r is either 3 or - 3. We will use this to calculate the three geometric means. Let's start with r=3.
Finally, let's calculate the geometric means when r=- 3.