I'm a little confused about exactly what you are trying to calculate; however, 7.95023E-4 means 7.95023 x 10^-4. So yes it is equal to 0.00079502 (you had an extra decimal in there).

Not sure if your math is right because you didn't tell us the figures you are working with.  OneP is one percent of the population, but I don't know why you are dividing fatalityCount by that number.  

s is a state.
So s.population is the total population of that state.
s.fatalityCount is the ammount of victims at work

for example, new york
population = 19378102
fatalityCount = 96

If 19378102 people would die at work then 100% would die, thank god it are 96 people.
So to know how many % dies:

fatalityCount / (population/100);
(bit different then listed in first post, but result is the same)