Lets get started :)
The First question:
Diameter = 20 ft
Radius =

of 20 (diameter) = 20 ft
Area formula of a circle is
A =

r²
=

(10)²
=100

ft²
≈ 314 ft²The answer will be the second optionThe Second question:
radius of circle = 12mm divided into 20 sectors area
A =

r²
=

(12)²
= 144

ft²
Divide into 20 equal sector areas =
≈ 22.6 mm²Your answer will be the third optionThe Third Question:
90°, sector area = 36

, Radius = ?



and

cancels out
We can now cross multiply
360 × 36 = 90r²
12960 = 90r²
Divide by 90 on either side

144 = r²
Take squareroot
x = 12 inYour answer will be the third option
2x-y =3
multiply by 4
8x - 4y = 12
3x +4y = 10 (unchanged equation)
------------------add
11x = 22
answer is A. the first.
first equation multiplied by 4 then sum to get 11x = 22
Answer:

Step-by-step explanation:
Given data :
Sample standard deviation, s = 15
Sample mean, 
n = 23
a). 98% confidence interval




∴ 

So, 98% CI is


