Using rectangles each of whose height is given by the value of the function at the midpoint of the rectangle's base (the midpoint rule), estimate the area under the graph of the following function, using first two and then four rectangles.

f(x)=6/x between x=1 and x=5

a. Using two rectangles, the estimate for the area under the curve is____?

(Round to three decimal places as needed.)

b. Using four rectangles, the estimate for the area under the curve is____?

(Round to three decimal places as needed.)