00:01
Starting with question one, which is the total person to years at risk for 2013.
00:16
So since the population remained constant at 100 throughout the year, the total is 100 persons per years.
00:30
Now for number two, which is the point prevalence on january 1st, 2013.
00:45
So here there were three cases of the disease x on january 1st.
00:54
So the point prevalence is equal to the number of cases on january 1st divided by the population on january 1st, which equals 3 over 100 times 100, which equals 3%.
01:11
Now for number three, which is the point prevalence again on june 1st, 2013.
01:35
So again, there were three cases of the disease x on june 1st.
01:43
So we will use the same point prevalence formula.
01:47
So we have 3 over 100 times 100, which equals 3%.
01:53
Now number 4 is the period prevalence for september 1st through the 30th.
02:12
So again, there were three cases of the disease x during this time.
02:19
So again, we will use the same period prevalence formula, which equals 3 over 100 times 100, which equals 3%...