Answer:
2.26 in
Explanation:
Given: the area of the slice is 4 in^2.
The formula for the area of a circle is A = (pi)(r)^2, where r is the radius.
Therefore, 
A = 4 in^2 = (pi)(r^2), or
 
 4 in^2
r^2 = ------------ = 1.273
 pi
Since the area of the slice is A = (pi)(r^2), and since (d/2)^2 = r^2 = d^2/4
A = (4 in^2) = (pi)(d^2 / 4) 
Solving for d^2, we divide both sides by pi/4, obtaining:
4 in^2
---------- = d^2 = 5.093 in^2
 pi/4
and so d = √5.093 = 2.26 in (to the nearest 100th)