Approximate the area under the graph of $f(x)$ and above the $x$-axis with rectangles, $f(x)=\frac{2}{x}+2$, from $x=1$ to $x=9$ using the following methods with $n=4$.
(a) Use left endpoints.
(b) Use right endpoints.
(c) Average the answers in parts (a) and (b)
(d) Use midpoints.

The area, approximated using the left endpoints, is 22.7 .
(Round to two decimal places as needed.)
The area, approximated using the right endpoints, is 19.15
(Round to two decimal places as needed.)
The average of the answers in parts (a) and (b) is 20.93
(Round to two decimal places as needed.)
The area, approximated using the midpoints, is $\square$
(Round to two decimal places as needed)

Step 1 ：Define the function \(f(x) = \frac{2}{x} + 2\).

Step 2 ：Define the interval from \(x = 1\) to \(x = 9\) and the number of subintervals \(n = 4\).

Step 3 ：Calculate the width of each subinterval \(h = \frac{b - a}{n} = 2.0\).

Step 4 ：Calculate the midpoints of each subinterval, which are \([2.0, 4.0, 6.0, 8.0]\).

Step 5 ：Evaluate the function at the midpoints and multiply by the width to get the area of each rectangle. The areas are \([6.0, 5.0, 4.67, 4.5]\).

Step 6 ：Sum up all the areas to get the total area. The total area is approximately 20.17 when rounded to two decimal places.

Step 7 ：Final Answer: The area under the graph of \(f(x)\) and above the \(x\)-axis, approximated using the midpoints, is \(\boxed{20.17}\).