A company producing electric motors has established that, on the average, a new employee can assemble N(t) components per day after t days of on-the-job training, as shown in the following table (a new employee s productivity increases continuously with time on the job):

Use left and right sums to estimate the area under the graph of N(t) from t = 0 to t = 60. Use three subintervals of equal length for each. Calculate an error bound for each estimate.