Based on a sample of 25 observations, the population regression model yi = 0 + 1x1 +

Based on a sample of 25 observations, the population regression model
yi = β0 + β1x1 + εi
was estimated. The least squares estimates obtained were as follows:
b0 = 15.6 and b1 = 1.3
The total and error sums of squares were as follows:
SST = 268 and SSE = 204
a. Find and interpret the coefficient of determination.
b. Test, against a two-sided alternative at the 5% significance level, the null hypothesis that the slope of the population regression line is 0.
c. Find a 95% confidence interval for β1.