Next, we multiply each entry by an appropriate constant.
We now need to multiply each entry by either 1 (for the first and last entry) or 2 (for the rest). We do this by putting the constants from the trapezoidal rule in column C for each entry:
A 
B 
C 
D 

1 
x 
f(x) 
Constants 

2 
2.0 
4 
1 

3 
3.2 
10.24 
2 

4 
4.4 
19.36 
2 

5 
5.6 
31.36 
2 

6 
6.8 
46.24 
2 

7 
8.0 
64 
1 
Then we just enter = C2*B2 into cell D2, and copy this down column D.
A 
B 
C 
D 

1 
x 
f(x) 
Constants 

2 
2.0 
4 
1 
4 
3 
3.2 
10.24 
2 
20.48 
4 
4.4 
19.36 
2 
38.72 
5 
5.6 
31.36 
2 
62.72 
6 
6.8 
46.24 
2 
92.48 
7 
8.0 
64 
1 
64 
Notice for example that in D2, we get (1)(f(2.0)) = (1)(4) = 4. The constants we are multiplying by correspond to the bolded entries in the Trapezoidal formula below:
(h/2)[1 f(x_{0}) + 2f(x_{1}) + 2f(x_{2}) + ... +2f(x_{n1}) + 1 f(x_{n})]
Finally, all we need is to sum everything up and multiply by h/2. (Remember that h is 1.2.)