What resources can i use to learn how to use a ti 83 calculator?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

How do you find the distance of each number from the mean

Maria heard on the radio that the high temperature that day would be to determine the temperature in degrees celsius, she used the formula , where c is the temperature in degrees celsius and f is the temperature in degrees fahrenheit.