Question

In an area of Russia, records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushels per acre).

Rainfall (inches)	Yield(Bushels per acre)
20.3	62.3
10.4	54.4
19.7	79.7
17.7	62.2
21.5	86.9
12.6	52
11.9	43
18.2	85.1
21.8	76.5

1. Create a scatterplot for the data above. The Yield is to be the response variable. Describe the form, direction and strength of the association between these two variables.

2. Calculate a LSRE that predicts yield of wheat from the amount of rainfall

3. Use your regression equation to predict the amount of wheat produced for a rainfall amount that is an example of extrapolation. Explain why you should not be confident of the result.

4. Calculate the correlation coefficient and the coefficient of determination and explain the meaning of each in the context of this situation.

5. Test to see, at the 5% level of significance, if the correlation is statistically significant

Answer 1

5.