common ratio = a4/a3 = a3/a2
8/a3 = a3/18
(a3)^2 = 8 * 18
(a3)^2 = 144
a3 = 12 or a3 = -12
common ratio = 8/12 or common ratio = 8/(-12)
common ratio = 2/3 or common ratio = -2/3
Answer: 12 or -12
Answer:
nope it would be B (1)
Step-by-step explanation:
The geometric mean of
and
is
.
So the geometric mean of 4 and 16 is
.
For this problem you can create a proportion.
Since 31,100 copies is 7.8% of the total copies spoke up to date you can make this proportion:
31,100. 7.8%
——— =. ———
x. 100%
Now you cross multiply and you will get
7.8x=3,110,000
After this you solve for x by isolating the variable.
7.8x/7.8. 3,110,000/7.8
x=398,717.949
Since the question asks you to round to the nearest whole number which is 7 then the final answer would be 398,718
Answer: There has been 398,718 copies sold to date.
Answer:
The first choice is the one you want
Step-by-step explanation:
Use geometric means to solve for a first. The formula is
and 64 = 15a and a = 64/15
That one was quite easy. Finding b is a bit more difficult.
The formula for finding b is
Solving for b:
Filling in we have
and
and
so b = 136/15
