Answer:
perimeter = (18 +9π) cm
area = (81 -20.25π) cm^2
Step-by-step explanation:
The perimeter of the shaded area is the circumference of the circle added to two sides of the square. The circumference of the circle is π times the diameter, so the perimeter is ...
p = 2(9 cm) + π(9 cm) = (18 +9π) cm
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The area of the shaded portion is the difference between the area of the square and the area of the circle. The area of the square is the square of the diameter. The area of the circle is π/4 times that value.
A = (9 cm^2) + (π/4)(9 cm^2) = (81 +20.25π) cm^2
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Comment on circle area
The formula you often see is ...
A = πr^2 . . . . r is the radius
since r = d/2, where d is the diameter, this can also be written as ...
A = π(d/2)^2 = (π/4)d^2
Here, the diameter of the circle is the same as the side length of its enclosing square, so the area of the circle is π/4 times the area of the enclosing square.
Mean: ( 9 + 7 + 6.5 + 7.5 + 7 + 8 + 5 + 6 + 7.5 + 8 ) : 10 = 7.15
Variance:
(Sigma)² = ( 1.85² + 0.15² + 0.65² + 0.35² + 0.15² + 0.85² + 2.15² + 1.15² + 0.35² + 0.85² ) : 10 ≈ 1.15
Answer: C ) 1.15
To find out end behavior, we always look at the largest exponent (3 in this case) and the sign of the term with the largest exponent (negative in this case). We can rule out the first two choices because since it is a cubic graph (exponent of 3) the graph will be pointing in opposite directions. Then, the negative tells us that as the x values approache infinity, the y values will approach negative infinity. So the correct answer is the last choice.
Hope this helps
