Answer:

Step-by-step explanation:

The least-square regression line has a slope of:
m=(nΣxy-ΣyΣx)/(nΣx²-ΣxΣx)
and a y-intercept of:
b=(Σy-mΣx)/n
In this case: n=7, Σxy=4899, Σy=391, Σx=85, Σx²=1153 so
m=(7(4899)-391*85)/(7(1153)-85*85))=1058/846
b=(391*846-85*1058)/(7*846)=34408/846
So the line of best fit is:
y=(1058x+34408)/846 and if we approximated this as your answers see to have done....
y=1.25x+40.67
Answer:
36π mi
Step-by-step explanation:
Area of a circle = πr²
Diameter = 12 mi. Therefore, radius=12/2 = 6 mi
πr²
π x (6)²
π x 36
Hence, the answer is 36π mi