Can someone explain how to find virulence, recovery rate, and transmission rate?

I'm reviewing rates for models of infectious diseases and as part of my homework I need to find virulence, recovery rate, and transmission rate. However, I can't find sources that explain them. Most give the symbol in an equation like threshold density or net reproductive rate without explaining how these variables are found.

Total population = 120,000
death rate to non-disease factors = 0.002 per capita per year
4500 infected individuals in the past year with 120 infected dead and 900 recovered. No immunity.

In calculating virulence, I'm using the amount dead from disease out of the total amount of infected individuals to determine the rate, correct? Do I divide...dead/infected individuals?

In recovery rate, I'm using the number of recovered from disease out of the total number of infected individuals to determine the rate of recovery? So do I divide to get the rate: recovered/total infected

For transmission rate, in finding the probability do I use the number of susceptible hosts and the number of infected individuals to calculate the rate? Do I multiply or divide or...am I just going about this wrong?

Some clarification would be immensely helpful. Thanks!