Seraphina is driving two hours to visit her family. for the first hour, she traveled at a speed of 58 miles per hour. then, in the second hour, she traveled at a speed of 67 miles per hour. what is the percentage increase of seraphina's speed? if necessary, round to the nearest tenth of a percent.

The percentage increase of Seraphina's speed is 15.52 %

Step-by-step explanation:

Total amount if time that Seraphina drove to visit her family is 2 hours.

For the first hour, she traveled at a speed of 58 miles per hour and in the second hour, she traveled at a speed of 67 miles per hour.

Increase in speed is the speed at which she travelled in the second hour - the speed at which she travelled in the first hour. It becomes

67-58 = 9 miles per hour

The percentage increase of Seraphina's speed is

(Increase in speed/ her speed in the first hour) × 100. This becomes

9/58 × 100

= 15.5172

15.52 %