Using Minitab software.

1. In 1997, 46% of Americans said they did not trust the media "when it comes to reporting the news fully, accurately and fairly." In a 2007 poll of 1010 adults nationwide, 525 stated they did not trust the media.

• At the = 0.05 level of significance, is there evidence to support the claim that the percentage of Americans that do not trust the media to report fully and accurately has increased since 1997?
• Will the results change if we are testing at 99% confidence level? Explain.

2. According to work done by Nick Wilson of Otago University Wellington, the proportion of individuals who cover their month when sneezing is 0.733. As part of a school project, Mary decides to confirm this by observing 100 randomly selected individuals sneeze and finds that 78 covered their mouth when sneezing. At the = 0.01 level of significance.

• What are the hypotheses for Mary's project?
• Verify the requirement for this hypothesis testing
• Does the sample evidence contradict Professor Wilson's? Explain.

3. A machine fills bottles with 64 fluid ounces of liquid. The quality-control manager determines that the fill levels are normally distributed with a mean of 64 ounces and a standard deviation of 0.42 ounce. He has an engineer recalibrate the machine in an attempt to lower the standard deviation. After the recalibration, the quality-control manager randomly selects 19 bottles from the line and determines that the standard deviation is 0.38 ounce. Is there less variability in the filling machine? Use =0.01 level of significance. What does it mean for the quality-control engineer to make a Type I error? A Type II error?