. An experiment was performed to compare the abrasive wear of two different laminated materials. 25...

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. An experiment was performed to compare the abrasive wear of two different laminated materials. 25 pieces of material 1 were tested by exposing each piece to a machine measuring wear. 14 pieces of material 2 were similarly tested. In each case, the depth of wear was observed. The samples of material 1 gave an average (coded) wear of 86 units with a sample standard deviation of 4, while the samples of material 2 gave an average of 94 with a sample standard deviation of 7. Can we conclude at the 0.05 level of significance that the abrasive wear of material 1 exceeds that of material 2 by more than 5 units? Assume the populations to be approximately normal with equal variances. . Suppose and 2 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. Use the two-sample t test at significance level .01 to test Ho: - = -10 versus Ha: - . An experiment was performed to compare the abrasive wear of two different laminated materials. 25 pieces of material 1 were tested by exposing each piece to a machine measuring wear. 14 pieces of material 2 were similarly tested. In each case, the depth of wear was observed. The samples of material 1 gave an average (coded) wear of 86 units with a sample standard deviation of 4, while the samples of material 2 gave an average of 94 with a sample standard deviation of 7. Can we conclude at the 0.05 level of significance that the abrasive wear of material 1 exceeds that of material 2 by more than 5 units? Assume the populations to be approximately normal with equal variances. . Suppose and 2 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. Use the two-sample t test at significance level .01 to test Ho: - = -10 versus Ha: -