Final answer:
The sum of the series 9 + 10 + ... + 70 is calculated using the formula for an arithmetic series and results in a total sum of 2449.
Step-by-step explanation:
To compute the sum 9 + 10 + ... + 70, you can use the formula for the sum of an arithmetic series: Sn = n/2(a1 + an). To find the number of terms n, you subtract the first term from the last term and divide by the difference (which is 1 for consecutive integers) and then add 1: n = (70 - 9)/1 + 1 = 62. Using the sum formula with the first term a1 = 9 and the last term an = 70 yields S = 62/2(9 + 70), which simplifies to S = 31 * 79, resulting in the sum S = 2449.