1. Despite the Equal Pay Act of 1963, in 1993 it still appeared that men earned more than women in similar jobs. In a random sample of 38 male machine tool operators, the mean hourly wage was found to be $ 11.38, with a sample standard deviation of $ 1.84. A random sample of 45 machine tool operators was taken and a mean hourly wage of $ 8.42 was obtained, with a sample standard deviation of $ 1.31. Based on these two samples, is it reasonable to conclude (at a level equal to 0.01) that operators earn more than $ 2.00 per hour than operators?

2. A credit and insurance organization has developed a new high-tech method of training new sales people. The company sampled 16 employees trained in the original way and found average daily sales of $ 688 with sample standard deviation of $ 32.63. They also took a sample of 11 employees trained with the new method and found an average daily sales of $ 706 with a sample standard deviation of $ 24.84. For 0.05, can the company conclude that the daily average sales increases with the new plan?

Donna Rose is a production supervisor for the Winchester Technologies disk drive assembly line. Winchester recently installed an audio system for background music at its facility, with the idea that the music would relax its workers and lead to greater productivity. Donna doubts this hypothesis, fears that music will be a source of distraction and cause a drop in productivity. He sampled the weekly output of the same six workers before having BGM and then installing the system. Their data is presented below. At the 0.02 level, has average production changed? Employee 1 2 3 4 5 6 Week without music 219 205 226 198 209 216 Week with music 235 186 240 203 221 205

4. A coal-fired power plant is considering two different systems to reduce the emission of pollutants. The first system reduces the emission to acceptable levels 68% of the time, based on 200 air samples. The second, more expensive system reduces it to acceptable levels 76% of the time, based on 250 samples. If the expensive system is significantly more effective than the other in reducing pollutant emissions to acceptable levels, then the plant management will install the expensive system. What system should be installed if the administration uses a significance level of 0.02 when making its decision?

5. Explain what the P-Value is and why is it useful in a hypothesis test?