The weight percent of silicon in six different rock samples, each containing different amounts of silicon, was measured by two different methods. The results are given in the table. Determine tcalc. tcake= Determine ttabie at the 95% confidence level. A list of t values can be found in the Student's t table. tiable Are these methods significantly different at the 95% confidence level? The methods are not significantly different at the 95% confidence level, The methods are significantly different at the 95% confidence level