Statistical HW

1. Compute the regression equation for the data below. What is the F value and significance for the regression?

X	Y
1	7
3	6
10	1
9	8
10	2
7	8
2	6
7	3
2	5
8	2
1	10

2. Compute the regression equation for the data below. What is the F value and significance for the regression?

X	Y
1	8
5	6
7	5
3	8
10	4
2	9
4	7
6	4
9	3
8	3

3. The time to encrypt a k byte record using an encryption technique is shown below. Fit a linear regression model to this data. Use visual tests to verify the regression assumptions. Is a linear regression the best choice, why or why not.

Record Size	Obs 1	Obs 2	Obs 3
128	386	375	393
258	850	805	824
384	1544	1644	1553
512	3035	3123	3235
640	6650	6839	6768
768	13887	14567	13456
896	28059	27439	27659
1024	50916	52129	51360

4. Do the same for the data below on house prices and square feet. How much on average does the value of a house increase by square foot (hint: what part of the regression equation might explain this)? Predict the price for a 2000 square foot house. For these houses, what portion is not explained by square feet? What is the coefficient of determination for this regression? What does that mean?

4.