The number of phone calls received in the second month is 25% more than the first month, which means:
Number of phone calls in second month = 1.25 x 4,264 = 5,330
To find the percent increase from the second month to the third month, we can use the percent increase formula:
Percent increase = (New value - Old value) / Old value x 100%
Using this formula, the percent increase from the second month to the third month is:
Percent increase = (6,396 - 5,330) / 5,330 x 100%
= 20%
Therefore, the percent increase in the number of phone calls from the second month to the third month is 20%.