Std. Err. t(21) p Coeff.
intercept 6.02331 17.1237 0.000000 103.1412
(1)time of grinding(L) 6.50329 7.5859 0.000000 24.6667
time of grinding(Q) 5.30991 -3.0342 0.006309 -8.0556
(2)feed quantity(L) 6.50329 -3.0412 0.006208 -9.8889
feed quantity(Q) 5.41941 -3.3966 0.002720 -9.2037
(3)ball size(L) 18.67928 -1.8559 0.077559 -17.3333
ball size(Q) 16.25822 -2.5081 0.020416 -20.3889
(4)feed size(L) 9.40588 -12.6522 0.000000 -59.5024
feed size(Q) 8.17766 4.8376 0.000088 19.7801
Table 3: Values of p and t.