Let the marks of the students in class 1 be

the average of these 12 marks is 90, so

which means

similarly, let

be the marks of the students in the second class,
so

which means

The 32 students averaged:
Answer:
The answer to your question is See the attachment
Step-by-step explanation:
Equation
(x - 8)² + (y + 5)² = 4
Process
1.- Write the standard equation of the circle
(x - h)² + (y - k)² = r²
2.- Find the center
The center are the letters h and k
h = 8 k = -5
3.- Find the radius
r = 2
4.- Graph the circle ( i will use geogebra)
See below
The formula for area in terms of radius is
... A = πr²
Solving this for r, we get
... A/π = r²
... r = √(A/π) . . . . . formula for the radius
For your given area, the radius is approximately
... r = √(401.92/3.14) = √128 = 8√2
... r ≈ 11.3 . . . yards
49.26 because 90-40.74=49.26