F. To compare the strengths of two pressure plywood samples of ten of each were selected and tested for breaking strength. The following data were obtained: Mean Σχο (Ex)²/n Group 1 35 12443 12250 Group 2 30 9167 9000 a) What is the 99% confidence interval estimate of the true difference between means of the two plywood? (2 Points) b) Can you conclude that the difference between the true means is significant at the 1% level without conducting a test of hypothesis? (2 Points) c) What is the basis for your conclusion in b)? (1 Points)