For the data given in problem 1 above, assume that graphical checks for fit, constancy of variance,
and normality are satisfied. Find:
a. the standard error of the slope of the regression equation, and
1b.
the 95% confidence limits of the slope.
c. find the sample correlation coefficient
d. what percentage of the variation of yi about y" is explained by regression?

1. The following table presents shear strengths (in kN/mm) and weld diameters (in mm) for a sample of spot welds. diameter 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0 Strength 51 54 69 81 75 79 89 101 98 102