Find the sum. Use the summation capabilities of a graphing utility to verify your result. 6 (91 + 8) i = 1 Step 1 6 Use the following property of summation to find the sum (9; + 8). n (a + b) = a, i = 1 n i = 1 i = 1 bi i = 1 Write the sum using the above property. 6 6 (91 + 8) = Step 2 i = 1 i = 1 6 9+ 8 i = 1 6 Since 9 is a constant, use the following property of summation to find the sum 9;- n W i = 1 = k i = 1 a i = 1 Using the above property, 6 i = 1 9i = i = 1 Hence, (1+2+ + 4+ 5+ 6) (21)