<prompt> Calculate the prevalence if incidence is 2 cases per 1000 population per year and mean duration is 4 years-8 cases per 1000 population2 cases per 1000 population0.5 cases per 1000 population32 cases per 1000 pupulation  <response>: .prevalence is the product of incidence and mean duration ,that is 2 4 per 1000 population.ref:park;s textbook,ed22 ,pg no 57 