Answer:
So the correct option is First one
i.e 
Step-by-step explanation:
Given:
Area of Shaded part = 9 π square feet
To Find :
Area of Circle = ?
Solution:
90 degree center angle is equivalent to an area of 9 Π square feet
So, 360 degree center is equivalent to area A which is the area of the complete circle.
So the Ratio will be
Setting the given statements in proportion:

On solving we get the required

So the correct option is First one
i.e 
Alternate Method:
Shaded part is of 90°
Area of Shaded part = 9 π square feet
And Full Circle is of 360° that is 4 sector of 90°



So the correct option is First one
i.e 
On solving this we get

Answer:
s=10
Step-by-step explanation:
Basically, the range rule-of-thumb is that the range is generally about four times the standard deviation.
<u>First, we find the range:</u>
Range=Maximum-Minimum
Range=100-60
Range=40
<u>Next, divide the range by 4 to get the standard deviation</u>
Range=4(Standard Deviation)
40=4(Standard Deviation)
10=Standard Deviation
Therefore, s=10, which is the standard deviation
Answer:
Step-by-step explanation:
This equation is written in slope-intercept form, meaning that the value next to the variable (7.50) is the rate (slope) and the other number is the y-intercept (9).
So you can say that you mowed the lawn at $9 up front and 7.50 every hour (or half-hour whatever you want).