Individual Homework Assignment (Due Feb 20)

This is a relatively simple assignment and it has two parts:

Part I:

This data file contains two entries: year and departure temperature from the average world wide temperature in 1899.

Thus you have 105 years worth of data and each year is independent.

Your task is to use the chi-squared method to compare the data against some linear model or a combination of different linear models if you think that is better, E.g. suppose your model is that the average temperature of the earth will rise 0.5 degrees C every hundred years (or 0.05 degrees per decade).

You should compute the chi^2 statistic and try to find the linear model that produces the lowest chi^2 sum.

This is relatively easy to do within Excel.

Don't be anal about this by doing the calculation on a per year basis (unless you want to write a computer program). You can average the data in 10 year intervals if you want.

Basically you want to test the data against various linear models, e.g. 0.5 C, 1.0 C, 1.5 C, 0.3 C or whatever, per century. Possibly you want to fit a series of linear models over different time periods.

Part II: The psychology department wants to determine if student gender is linked with area of interest in the field of psychology. A survey is distributed to psychology majors, who are instructed to endorse one (and only one) interest area.

```          Clinical      Social        Biological

Men           15           23            10
Women          8           25            40
```
Perform a two-way chi-square analysis to test the null hypothesis that there is no relation between gender and interest area.