7:45 KB/S 26 11 914 STA 304 CAT_2.pdf a STA 304: TEST OF HYPOTHESIS DATE: 11/01/2022 CAT 1. In a pharmaceutical industry, repellency of a parasite is assumed to be influenced by environmental temperature, concentration of a drug and mode of drug application. To determine how these factors influence repellency, a multiple linear regression analysis was carried out on 195 observations and extract of the output was as shown below Regression Coefficients Model Coefficients Std. Error Sig. Constant) . 106 1.338 -.079 .938 concentration 766 122 6.279 .001 temperature .229 .233 .983 264 Mode of application .025 .015 1.643 .120 Formulate the relevant hypotheses and test on the significance of the predictor variables using both p-values and the test statistics values [10mks] 2. M. G. Patel & Co. wanted to assess the impact of R & D expenditure on annual profit. The following table presents the information for the preceding eight years. ears R & D expenditure (ksh '000) Annual profit (ksh '000) 2013 45 2012 42 2011 41 2010 60 2009 30 2008 34 2007 25 2006 20 Using a simple regression model, help the company determine whether R & D expenditure influences annual profit of the company at 99% confidence interval [10mks] 3. Jeffrey, as an eight-year old, established a mean time of 16.43 seconds for swimming the 25-yard freestyle, with a standard deviation of 0.8 seconds. His dad, Frank, thought that Jeffrey could swim the 25-yard freestyle faster using goggles. Frank bought Jeffrey a new pair of expensive goggles and timed Jeffrey for 15 25-yard freestyle swims. For the 15 swims, Jeffrey's mean time was 16 seconds. Frank thought that the goggles helped Jeffrey to swim faster than the 16.43 seconds. Conduct a hypothesis test using a preset a = 0.05. [5mks] 4. A manufacturer of salad dressings uses machines to dispense liquid ingredients into bottles that move along a filling line. The machine that dispenses salad dressings is working properly when 8 ounces are dispensed. Suppose that the average amount dispensed in a particular sample of 35 bottles is 7.91 ounces with a variance of 0.03 ounces squared. Is there evidence that the machine should be stopped and production wait for repairs? The lost production from a shutdown is potentially so great that management feels that the level of significance in the analysis should be 99%. [5mks] NB: Show how you arrive at your choice for question 6 and 7 [10mks] 5. A statistics instructor believes that fewer than 20% of Evergreen Valley College (EVC) students attended the opening night midnight showing of the latest Harry Potter movie. She surveys 84 of her students and finds that 11 of them attended the midnight showing. At a 1% level of significance, an appropriate conclusion is; a. There is insufficient evidence to conclude that the percent of EVC student who attended the midnight showing of Harry Potter is less than 20%. b. There is sufficient evidence to conclude that the percent of EVC students wh attended the midnight showing of Harry Potter is more than 20%. c. There is sufficient evidence to conclude that the percent of EVC students who attended the midnight showing of Harry Potter is less than 20%. d. There is insufficient evidence to conclude that the percent of EVC students who attended the midnight showing of Harry Potter is at least 20%. 6. Previously, an organization reported that teenagers spent 4.5 hours per week, on average, on the phone. The organization thinks that, currently, the mean is