
Piecewise model
I have a piecewise model problem that i cannot figure out below is the following problem any help would be appreciated.
2. Find a piecewise model for the data and graph it together with the original data points. You may want to use a parabola for the points corresponding to the years 1990  1994 and a line corresponding to the years 1994  1996. Round the coefficients to three decimal places. Does the model provide a good fit for the data points? Explain.
Below this is all the information for the problem
Greenhouse Gas Emissions in Australia
Australia is a relatively small producer of greenhouse gases, accounting for approximately 1.4% of global emissions. However, its emissions per capita rank third amongst industrialized countries. This is due to particular circumstances including an abundance of fossil fuel resources, a dispersed population with a consequent heavy dependence on fossil fuel based transport, and a relatively rapid rate of population growth.
The following table gives Australia's net greenhouse gas emissions in Mt CO2e by year. Mt is the abbreviation for megaton, which is one million tons. CO2e represents carbon dioxide equivalent emissions. CO2 equivalent emissions are calculated by measuring the global warming potential of a greenhouse gas relative to that of CO2. For example, carbon dioxide is assigned a global warming potential (GWP) of 1 and methane a GWP of 21. That is, one ton of methane is equivalent to 21 tons of carbon dioxide in terms of its effect on global warming.
Year 1990 1991 1992 1993 1994 1995 1996
Mt CO2e 384.9 386.1 386.9 389.6 394.2 406.8 419.3
Source: National Greenhouse Gas Inventory

the parabola for 19901994, based on my calculation:
0.506X^2+0.345X+384.956=Y
I treated 1990 as year 0.
for the general solution, someone already posted there.
http://www.physicsforums.com/showthread.php?t=97382
