I am not sure about the formula but if you subtract 8,884 from 10,712 you get 1,828. Then, if you divide that by 4 you get 457. 457 fph(feet per hour) should be the climbers vertical speed.
Thats the same thing as 0.3 x 10
when mulitplying by 10, 100, 1000, etc.
what i do is i move the decimal place over how many zeros there are so there is one zero and that means you need to move the decimal place over one space to the right so the answer is
3
I hope this helps but the answer is 913 hope it helps
Your answer is d, you can not use 6 and the equation be right.