Question 62300: ok, i have 2 find out the formula for this table and ive tried all that i can think of, here it is.
Age (yr) 20 30 40 50 60 70
Pulse rate (beats/min) 175 166 157 148 139 130
Write an equation in function notation for the relation.
Found 2 solutions by tutorcecilia, funmath:
Answer by tutorcecilia(2152)   (Show Source):
You can put this solution on YOUR website! This is a linear equation. That is, as age increases, pulse rate decreases.
Use the formula for a slope and the slope-intercept formula to solve.
.
The x's are the ages.
The y's are the pulse rates.
So, match-up the ages and pulse rates to form a list of coordinate pairs:
(20, 175)
(30, 166)
(40, 157)
(50, 148)
(60, 139)
(70, 130)
.
Slope=m=(y1-y2)/(x1-x2)[use the formula for the slope of a line]
m=(175-166)/(20-30) [plug-in the values and solve for the slope of the line]
m=9/-10=-9/10
.
y=mx+b [use the slope-intercept formula]
175=(-9/10)(20)+b [plug-in the values and solve for b]
175=118+b
175+18=b
193=b [plug the slope and y-intercept (b) back into the equation}
.
y=mx+b
y=(-9/10)x+193 [the equation of the line]
or f(x)=(-9/10)x+193 [function notation]
Answer by funmath(2933)  (Show Source):
You can put this solution on YOUR website! Age (yr) 20 30 40 50 60 70
Pulse rate (beats/min) 175 166 157 148 139 130
Write an equation in function notation for the relation.
If you were to plot this relation letting x= age and y= pulse rate, you would find that if you connected the dots they make a perfect line.
In order to write a linear function, you need a point and a slope. We have plenty of points, let's find the slope using the slope formula:  , m=slope, (x1,y1) and (x2,y2) are points.
Let (x1,y1)=(20,175) and (x2,y2)=(30,166)
Now that we have the slope and a point we can use the point slope formula.
m=-.9 and (x1,y1)=(20,175)
Remember, y=pulse rate and x=age, in function notation:
 where pulse rate is a function of age.
Happy Calculating!!!
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