# Sample data is closer to a simple linear model or an exponential model?

• Apr 14th 2009, 10:59 PM
Lok
Sample data is closer to a simple linear model or an exponential model?
A guy wants to know if this data sample is closer to a simple linear model or to an exponential model.
The table below represents 4 machines. We want to know the cost in function of the age of the machine. So X:age and Y:maintenance cost

Age 1 | 1.7 | 2 | 2.25
cost 0.5| 0.6 | 1.2 | 2

Either linear
Y = B_0 + B_1X
or Exponential
Y = ae^{bx}

Any tips to get me started?
• Apr 15th 2009, 12:58 AM
mr fantastic
Quote:

Originally Posted by Lok
A guy wants to know if this data sample is closer to a simple linear model or to an exponential model.
The table below represents 4 machines. We want to know the cost in function of the age of the machine. So X:age and Y:maintenance cost

Age 1 | 1.7 | 2 | 2.25
cost 0.5| 0.6 | 1.2 | 2

Either linear
Y = B_0 + B_1X
or Exponential
Y = ae^{bx}

Any tips to get me started?

Fit the data to each model and look at r^2.
• Apr 15th 2009, 01:11 AM
Lok
How do I fit the data to the models? :(
• Apr 15th 2009, 01:18 AM
mr fantastic
Quote:

Originally Posted by Lok
How do I fit the data to the models? :(

Use technology. eg. TI-89 calculator, suitable software. It can even be done by hand (but very tedious).