Lower & Upper Estimate...PLEASE HELP

[nikchic5]

Ok here is the question....if anyone could help it would be really appreciated!
A table of values of an increasing function f is shown. Use the table to find lower and upper estimates for
the interval from 0 to 35 of f(x)dx . Use 5 equal subintervals.
Here is the table....

x 0 7 14 21 28 35
f(x) -49 -38 -22 -8 15 34


If you could please help me find the lower and upper estimates...thanks so much!!!

 

[Gene]

Since it is increasing the lower estimate uses dx=7

  0   7  14 21 28  
-49 -38 -22 -8 15

(-49 - 38 -22 -8 +15)*7 = -714

The upper estimate is

  7  14 21 28 35  
-38 -22 -8 15 34

(-38 -22 -8 +15 +34)*7 = -133

Not a very good estimate but...