Question 1141165
have sigma so use z
half-interval is 0.15 inches
=z*sigma/sqrt(n)=2.576*0.2/sqrt(n), where z(0.995)=2.576
square both sides and multiply through by n
0.15^2*n=2.576^2*0.2^2
0.0225n=0.2654
11.79 or 12