Answer:
25.85
Step-by-step explanation:
The area of a circle is given by A = π * r²
We have the value of the area, so we clear r:
r² = A / π
r² = 2100 / π = 668.45
r = √668.45 = 25.85
Sample size=n=250
sample proportion=p=0.4
95% confidence interval so significance level α=1-0.95=0.05
So, α/2=0.025
z_( α/2)=1.960 (value taken from statistic z-table)
use formula;
p(+/-)z_(α/2)square root(p(1-p)/n)
(0.4-1.960 sq.root(0.4(1-0.4)/250), 0.4+1.960 sq.root(0.4(1-0.4)/250))
(-0.2073,0.4607) (estimation of population proportion)
