The rate of​ healing, A′(t)​(in square centimeters per​ day), for a certain type of abrasive skin wound is given approximately by the table. t 0 1 2 3
A′(t) 0.91 0.83 0.76 0.69

t 4 5 6 7
A′(t) 0.62 0.58 0.48 0.44 ​

Use left and right sums over five equal subintervals to approximate the area under the graph of A′(t) from t=0 to t=5.

The left​ sum, L5​, is .
The right​ sum, R5​, is .