7. (06.03 HC) A continuously-decreasing function that is concave down on the interval [3, 7] is represented by the table. 3 4.5 5 6.1 7 f(x) 1.946 1.705 1.609 1.361 1.099 Part A: Find the left Reimann sum estimate of ( 7(x)ax, based on the subintervals given in the table. (4 points) Part B: Write the midpoint Reimann sum that estimates ( f(x)ax, based on the subintervals given in the table. (4 points) Part C: Determine whether the left Reimann sum estimate is an overestimate or an underestimate, based on the properties of the function. (2 points)