Answer:
3.471 + 7.2516 x
Step-by-step explanation:
Given the data:
 (1,3) (2,0) (5,-8) (9, -25) .
X:
1
2
5
9
Y:
3
0
-8
-25
The line of best fit for the data given can be obtained using an online regression calculator :
The equation of best fit for the data is thus;
Best fit equation; y = -3.471 + 7.2516x
Intercept = - 3.471 ; 
Slope = 7.2516
 
        
             
        
        
        
Direct Proportion functions look like this:
y=kx
'k' is the constant of proportionality and in this case its 7.5 or 15/2.
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When x=1, y=7.5
When x=2, y=15
When x=3, y=22.5
Therefore y is directly proportional to x.
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DIRECT PROPORTION EXPLAINED:
Say a football costs £7.50. If you buy one football you'll have to pay out £7.50, but if you you buy two footballs you'll have to pay out £15.00. Therefore the cost of the football(s) is directly proportional to the amount of footballs you buy. C=cost, f=football(s) and C<span>∝f, therefore C=kf, but as k=7.5, C=7.5f.
INVERSE PROPORTION EXPLAINED:
If it were to take 8 hours for one bricklayer to set up a wall, how long would it take for two bricklayers to set up a wall? The answer in this case would be 4 hours.
T=time to set up a wall
b=bricklayer(s)
Therefore T</span><span>∝1/b, and T=k/b. In this case k=8 so T=8/b.
When b=1, T=8.
When b=2, T=4.
We'd say that the time it would take for bricklayers to set up a wall would be inversely proportional to the amount of bricklayers available.</span>
        
             
        
        
        
First, square both sides. This will cancel out the radical. 

(a^2 = b + 6)
Then subtract 6 from both sides 
b = a^2 - 6
 
        
             
        
        
        
Answer:
26.66667 yards of carpet (240/9)
Step-by-step explanation:
 
        
             
        
        
        
You would multiply 32,000 x 0.05 = 1,600 so
1,600 x 4 = 6,400
So the population would grow by 6,400 every 4 years.