Which system is equavilent to (3x^2-4y^2 =25
-6x^2 -2y^2=11

a ) n = 1667

b) n= 5192

c) n=1500

Step-by-step explanation:

c= 95%

Expected value = E.v= 300 , 170 , 100

R = 35000-10000=25000

σ = R / 4 = 25000 / 4 = 6250

For sample size

b = ( zα/2  / 2σ  / E )^2

where 1-α = 0.95 and

zα/2 = 1.96

then putting values one by one of E we get

E.v = 300

  n= 1667

E.v = 170

n=5192

E.v =100

n= 1500

so for

a ) n = 1667

b) n= 5192

c) n=1500