Final answer:
To find the percent of increase, calculate the difference between the current and previous numbers, and express it as a percentage. In this case, the percent increase is approximately 65.0%.
Step-by-step explanation:
To find the percent of increase, we need to calculate the difference between the current number of people with cell phones and the previous number, and then express that difference as a percentage of the previous number.
Last year, there were 140 people with cell phones. This year, the number has increased by 65%, which is equivalent to multiplying it by 1 + 0.65 = 1.65.
The new number of people with cell phones is 140 * 1.65 = 231. The increase is 231 - 140 = 91.
Therefore, the percent increase is (91 / 140) * 100 ≈ 65.0%.