CASE 3:
GRAPHING THE TB EPIDEMIC (1996-2004)
Use the graph to stretch your math skills and explore the impact of the HIV epidemic on the number of TB cases in South Africa.
The line in the graph is composed of data points that tell us the number of TB cases each year.
STEP 1 Place your cursor over the points of the line that show TB cases in 1996.
STEP 2 Place your cursor over the points of the line that show TB cases in 2004.
Below you can see how we can mathematically determine the TB trend for the years between 1996 and 2004 in South Africa, now that we know the number of cases for this period.
There is a direct relationship between the year and the number of TB cases reported. We call this a linear relationship, and it has a unique, defining equation.
| Solve for "m" | Solve for "b" | What is the formula? |
|
m = (data2 – data1)/(year2 – year1) m = (1750 – 405)/(2004 – 1996) m = 168.13 |
b = y – mx b = (750 – 168.13) * 2004 b = 336,182.52 |
y = 168.13x – 336,182.52 |
South Africa has almost 50 million residents. With the TB trend you just calculated, how many actual TB cases would you predict in South Africa for 2007?
