A 82 kg diver steps off a 14 m tower and drops from rest straight down into the water. If he comes to rest 4.1 m beneath the surface, determine the average resistance force exerted on him by the water

A 82 kg diver steps off a 14 m tower and drops from rest straight down into the water. If he comes to rest 4.1 m beneath the surface, determine the average resistance force exerted on him by the water.

I tried to solve the problem using this method: https://www.youtube.com/watch?v=lgr1Qf-vo8o&ab_channel=JorgeGandara , but when I input my problem of 2744 N, the homework website says it's wrong.