Answer:
I think it's 3.5, but this information is super vague, so try to uhh scroll down to see if there's more information
Step-by-step explanation:
 
        
             
        
        
        
Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
        
                    
             
        
        
        
Answer:
 The forecast is accurate within plus or minus 3.2 units
Step-by-step explanation:
Mean Absolute Deviation is a statistical measure of dispersion from forecast. It measures accuracy level of predicted forecast, by averaging the difference between absolute value of each error from forecasted value. 
MAD for a forecast states that : Forecast is accurate within the expected range variation of Mean Absolute Deviation. 
So : If the MAD for a forecast is 3.2, we can say that -  The forecast is accurate within plus or minus 3.2 units 
 
        
             
        
        
        
Answer:
y = 2x-5
y=-x+4
Step-by-step explanation:
Just need to solve the:
x+y=4
y-2x=-5
And we have:
x=3
y=1
Then replace x and y into the answer to find the correct one