Process Capability. R. Morris and E. Watson studied various aspects of process capability in the paper “Determining Process Capability in a Chemical Batch Process” (Quality Engineering, Vol. 10(2), pp. 389–396). In one part of the study, the researchers compared the variability in product of a particular piece of equipment to a known analytic capability to decide whether product consistency could be improved. The following data were obtained for 10 batches of product. 30.1 30.7 30.2 29.3 31.0 29.6 30.4 31.2 28.8 29.8 Construct a stem-and-leaf diagram for these data with a. one line per stem.b. two lines per stem.c. Which stem-and-leaf diagram do you find more useful? Why?

2. A researcher had rats engage in a lever-press task for either a small, medium, or larger reward. The number of lever presses was the dependent variable. The data were as follows: Reward Size Small Medium Large 1 4 6 4 3 5 1 4 4 2 5 T = 13 SS = 2.75 T= 6 T= 20 SS = 9 SS = 2 EX2 = 165 a. Do the data indicate that reward size had a significant impact on lever-pressing? Use the hypothesis testing steps & p = .05. Compute any necessary post-hoc tests. b. Compute eta-squared to measure the effect size.

PETROGAS is testing new filters for its motorbikes. One brand of filter (Filter A) is placed in one motorbike, and the other brand (Filter B) is placed in the second motorbike. Random samples of air released from the motorbikes are taken at different times throughout the day. Pollutant concentrations are measured for both motorbikes at the same time. The following data attached represent the pollutant concentrations (in parts per million) for samples taken at 20 different times after passing through the filters. a. Test the hypothesis that the mean for the pollutant concentration for Filter B is greater than 30. Use the 1% level of significance. b. Construct a 95% confidence interval for the difference in mean pollutant concentration, where a difference is equal to the pollutant concentration passing through Filter A minus the passing through Filter B. c. Using the 5% significance level, determine whether there is evidence that mean for the pollutant concentration for Filter A…

You also conducted a review of the research literature and found that similar studies examining the relationship between alcohol consumption and liver cancer found the following: Smithson et al. RR 3.3 (95% CI:1.95-5.20)  Ribera et al. RR 2.1 (95% CI:1.17-3.33)  Gonzalez et al. RR 2.75 (95% CI 2.26-3.45) Which one of Hill’s criteria does this illustrate? Explain.