c. Find a 95% confidence interval for the true slope of the line. Interpret the result. Conduct a test (at a=0.05) to determine if the true slope of the line differs from 0.
      
     Apparent   Porosity (%) (y) Mean Pore Diameter (x)   18.8 12   18.3 9.75   16.63 7.35   6.9 5.35   17.1 10.95   20.4 16.8