Answer:

Step-by-step explanation:
The sum of an infinite geometric series is expressed according to the formula;
where;
a is the first term of the series
r is the common ratio
If the sum of an infinite geometric series is three times the first term, this is expressed as 
Substitute
into the formula above to get the common ratio r;


open the parenthesis

subtract 3 from both sides

<em>Hence the common ratio of this series is </em>
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The graph is misleading because it appears to be showing a huge increase, however, it is showing this increase over a huge time span of 13 years, which is actually quite a small amount for only a few hundred customer increase.
Answer:
The signup fee is $17
Step-by-step explanation:
we know that
The equation in point slope form is equal to

where
m is the slope or unit rate of the linear equation
(x1,y1) is a ordered pair of the line
Let
x -----> the number of months
y -----> the total cost of a gym membership
In this problem we have
The slope of unit rate is equal to

The ordered pair is

substitute
----> equation in point slope form
Convert to slope intercept form
---> equation in slope intercept form
The y-intercept is the signup fee (value of y when the value of x is equal to zero)
therefore
The signup fee is $17