Please complete this Lab by the end of the class period and submit your answers on Blackboard. This assignment may be completed either as individuals or small groups. In you analysis please make sure your work is your own. Do not copy and paste from another student word for word.
1. An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow.
For a 0.05 significance level, what is the decision regarding the hypothesis that the training was effective in improving customer relationships?
2. A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected and their times (in seconds) to access the website with the old and new designs were recorded. The results follow.
Let α = 0.05. Is the mean time to access the new website design shorter, or is (time for the old design - time for the new design) greater than zero? Perform the appropriate test to determine significance. Is there a significant difference in the web site access times according to the p-value?.
3. Suppose an automobile manufacturer designed a radically new lightweight engine and wants to recommend the grade of gasoline that will have the best fuel economy. The four grades are regular, economy, premium, and super premium. The test car made three trial runs on the test track using each of the four grades. The miles per gallon were recorded for each grade. At the 0.05 level, can we reject the null hypothesis? If so which sets of fuel show significant differences according to the Tukey post-hoc test?
