I we consider her running times as an arithmetic series with common difference:
43.13 - 43.1 = -.03/2 = -.015, Shelly's time in the fourth race will be 43.1 - .015 = 43.085.
The length of the other leg is 12 cm
I'm Unsure, But Here's What I Found.
9.99×65=649.35
10.68×65=694.2
((10.68÷9.99)−1)×100=6.9%
1 mile= 5280 feet
1/5280= 4.25/x This is a proportion.
5280 * 4.25= 22440
22440/1= 22440
4 1/4 miles= 22440 feet
Hope this helps! :D