The following data represent a random sample of 15 observations. Assume that Y is a linear function of X and a normally distributed disturbance term with a mean of zero and a constant variance. In other words: Y = a + bX + u, u ~ (0,2)

Obs	X	Y
1	80	48
2	6	44
3	15	14
4	9	43
5	64	58
6	99	54
7	63	34
8	80	31
9	52	26
10	17	22
11	26	68
12	87	55
13	56	35
14	36	38
15	32	66

6. Calculate the standard errors for a and b (sa and sb). Show the formulas, find their values, and discuss the interpretation of each of them. 7. Compute the confidence interval (alpha = 0.05) and the t-statistic for b. Show the formulas, find their values, and discuss the interpretation of each of them. 8. Calculate the R2 for the regression, show the formula, the value, and describe its meaning. 9. Graph the data points and the sample regression function. Identify the slope and the intercept term. Label the data points and graphically indicate the residual for each observation. Add a vertical dashed line for the mean of X and the horizontal dashed line for the mean of Y. Does the regression function pass through the intersection of these two lines?