An experiment was performed to compare the wear of different coating materials on the cutting tools. Coating material 1:

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An experiment was performed to compare the wear of
different coating materials on the cutting tools. Coating material
1: 11 pieces of clothing were tested, which gave an average wear of
85 units with a sample standard deviation of 4 units. Coating
material B: 10 pieces were tested, which gave average wear of 81
units with a sample standard deviation of 5 units. The population
is normal. Can we conclude that the population variances
of material A and material B are different? 2) Can we
conclude that the abrasive wear of material A exceeds that of
material B if the population variances of material A and B are
equal? Use 0.05 level of significance.