Simple equation using TI-83 calculator

1st let me say hello and this is my 1st post on this site, I've been googling the internet because I am very depeserate. I hope to be a part on your math community here.

I need to know what keys to hit to solve this simple math problem. I'm using a TI-83 calculator. I'll write the problem out since I don't know how to type in exponents.

(8 times 10 to the 4th power) x (7.5 times 10 to the negative 6) x (4.4 times 10 to the 15th) / (1.1 times 10 to the 4th) x (2.5 times 10 to the 3rd)4

The last number 4 is to the 4th power and not 4 times. Again I do not know how to type exponents.

I know the answer is .00614 but I need to know how to get that answer. If someone is kind enough to tell me which keys to hit to solve the problem. PS I know how to use the shift key so to make things shorter you can just say the name of the key. I also know how to use the negative. I think I'm making a mistake on the bottom of the fraction. Could be something as simple as a parenthases but I've been trying for an hour now...

Please help