TEXT BOOK (ISBN10: 1111837260) ====9781111837266 Pagano, Robert R. Understanding Statistics in the Behavioral Sciences by 1. Chapter 15, # 4, 8, 10, 13, 20, 23, 26 4). When doing an experiment with many groups, what is the problem with doing t test between all possible groups without any correction? Why does use of analysis of variance avoid the problem? 8).What are the assumption underlying the analysis of variance? 10). Find Fcrit for the following situations: a). df(numerator)= 2, df(denominator) = 16, =0.05 b). df(numerator)= 3, df(denominator) = 36, =0.05 c). df(numerator)= 3, df(denominator) = 36, =0.01 13). For each of the variables identified in question 12 (variables that affect power of one way analysis of variance technique), state how power is affected if the variable is increased. Use the equation fo Fobt on p.421 to justify your answer. 20). Assume you are nutritionist who has been asked to determine whether there is a difference in sugar content among the three leading brands of breakfast cereal (Brands A, B and C). To assess the amount of sugar in the cereals, you randomly sample six packages of each brand and chemically determine their sugar content. The following grams of sugar were found. Breakfast Cereal A B C 1 7 6 2 5 4 3 3 4 3 7 5 2 4 7 6 7 8 a). Using the conceptual equation of the one way ANOVA, determine whether any of the brands differ in sugar content. Use =0.05 b).Same as part a, except use the computational equations. Which do you prefer? Why? c). Do a post hoc analysis on each pair of means using the Turkey HSD test with =0.05 to determine which cereals are different in sugar content d).Same as part c, but use the Scheffe test. e). Explain any differences between the results of part c and part d 23). Assume you are employed by a consumerproducts rating service and your assignment is to asses car batteries. For this part of your investigation, you want to determine the whether there is a difference in useful life among the top of the line car batteries produced by three manufactures (A, B and C). To provide the data base for your assessment, you randomly sample 4 batteries from each manufacturer and run them through laboratory tests that allow you to determine the useful life of each battery. The following are the results given in months of useful battery life: Battery Manufacturer A B C 56 46 44 57 52 53 55 51 50 59 50 51 a). Use the analysis of variance with =0.05 to determine whether there is a difference among these three brands of batteries b). Suppose you are asked to make a recommendation regarding the batteries based on useful life. Use the Turkey HSD test with =0.05 to help you with your decision. 26). A university researcher knowledgeable in Chinese medicine conducted a study to determine whether acupuncture can help reduce cocaine addiction. In this experiment, 18 cocaine addicts were randomly assigned to one of three groups of 6 addicts per group. One group received 10 weeks of acupuncture treatment in which the acupuncture needles were inserted into points on the outer ear where stimulation believed to be effective. Another group, a placebo group, had acupuncture needles inserted into points on the ear believed to believed not to be effective. The third group received no acupuncture treatment; instead, addicts in this group received relaxation therapy. All groups also received counselling over the 10week treatment period. The dependent variable was craving for cocaine as measured by the number of cocaine urges experienced by each addicts in the last week of treatments. The following are the results. Acupuncture+ counselling Placebo +Counselling Relaxation therapy + counselling 4 8 12 7 12 7 6 11 9 5 8 6 2 10 11 3 7 6 a). Using=0.05, what do you conclude? b). If there is significant effect, estimate the size of effect using W^2 c). This time estimate the size of effect using n2 d). Explain the differences in answers between part b and part c 2. Chapter 16, # 11, 12, 13 11). It is theorized that repetition aids recall and that learning of new material can interfere with the recall of previously learned material. A professor interested in human learning and memory conducts a 2 x 3 factorial experiments to investigate the effect of these two variables on recall. The material to be recalled consist of a list 16 nonsense syllable pairs. The pairs are presented one at a time for 4 seconds cycling through entire list, before the first pair is shown again. There are three levels of repetition : Level one in which each pair is shown 4 times; level 2 in which each pair is shown 8 times and level 3 in which each pair is shown 12 times. After being presented the list the requisite number of time prior to testing for recall each each subject is required to learn some intervening material. The intervening material is of two types. Type1 which consist of a number pairs, and type two which consist of nonsense syllable pairs. After the intervening material has been presented, the subjects are tested for recall of the original lists of 16 syllable nonsense pairs. Thirty six college fresh men serve as subjects. They are randomly assigned so that there are six per cell. The following score are recorded; each is the number of syllable pairs from list correctly recalled Intervennig material (low variable) Number of Repetitions (Column variable) Number pairs 4 times 8 times 12 times 10 11 16 12 16 14 12 15 11 15 16 13 14 10 13 14 15 16 8 7 11 13 14 12 4 5 9 10 16 15 5 6 8 9 12 13 Nonense syllable pairs a). What are the Null hypotheses for this experiment? b). Using =0.05, what do you conclude ? Plot a graph of the cell means t help you interpret the result 12). Assume you have accepted a position as a chief scientist for a leading agricultural company. Your first assignment is to make a recommendation concerni9ng the best type of grass to grow in a the pacific Northwest and the best fertilizer for it. To provide the database for your recommendation having just graduated Summa Cum Laude, you decide to conduct an experiment involving a factorial independent groups design. Since there are three types of grass and two fertilizers under active consideration the experiment you conduct is 2x3 factorial, where the A variable is type of fertilizer and B variable is the type of grass. In your field station, you duplicate the soil and the climate of the pacific Northwest. Then you divide the soil in 30 equal areas and randomly set aside 5 of each combination of treatments. Next, you fertilize the areas with appropriate fertilizer and plant in each area the appropriate grass seed. There after all areas are treated alike. When the grass has grown sufficiently , you determine the number of grass blades per square inch in each area. Your recommendation is based on this dependent variable . The denser the grass the better. The following score are obtained. Number of grass blades per square inch Fertilizer Red Fescue Kentucky blue Green Velvet Type 1 14 15 15 17 20 19 16 17 12 18 15 22 10 Type 2 11 25 11 7 10 6 15 11 11 8 8 13 18 10 14 12 19 a). What are the Null hypotheses for this experiment? b). Using =0.05, what are your conclusions? Draw a graph of cell means to help you interpret the result 13). A sleep researcher conducts an experiment to determine whether a hypnotic drug called drowson which is advertised as remedy for insomnia, actually does promote sleep. In addition, the researcher is interested in whether a tolerance to the drug develops with chronic use. The design of the experiment is a 2x 2 factorial independent groups design. One of the variables is the concentration of Drwoson. There are two levels: (1) zero the concentration (placebo) and (2) the manufacturer's minimum recommended dosage . The other variable concerns the previous use of Drowson. Again there are two levels: (1) subjects with np previous use and (2) chronic users. Sixteen Individuals with sleep onset insomnia (difficult in falling asleep) who have had no previous use of Drowson are randomly assigned to the two concentration conditions. Such that there are eight subjects in each condition. Sixteen chronic users of Drowson are also assigned randomly to the two conditions, eight subjects per condition. All subjects take their prescribed \"medication\" for 3 consecutive nights and the time to fall asleep is recorded. The scores shown in the following table are the mean times in minutes to fall asleep for each subject, averaged over the 3 days: Concentration of Drowson Previous Use Placebo No previous use 45 53 30 47 48 58 33 35 62 55 40 31 70 64 50 39 47 68 52 46 52 64 60 49 55 58 58 50 62 59 68 55 Chronic use Minimum recommended Dosage a). What are the Null hypotheses for this experiment? b). Using =0.05, what do you conclude ? Plot a graph of the cell means t help you interpret the result