In a study of fertilizers, researchers randomly selected 25 corn farms that use Brand A fertilizer and 25 corn farms that use Brand B fertilizer to participate. Each corn farm that uses Brand A was matched with a corn farm of similar acreage and soil type that uses Brand B. The difference in the number of bushels of corn produced in one growing season was determined for each pair. What type of study is this? (A) An observational study (B) An uncontrolled experiment (C) A randomized comparative experiment (D) A matched pairs experiment (E) A randomized complete block design experiment

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An article in the journal Applied Nutritional Investigation reported the results of a comparison of two different weight-loss programs (Liao, 2007). In the study, obese participants were randomly assigned to one of two groups and the percent of body fat loss was recorded. The soy group, a low-calorie group that ate only soy-based proteins (M= 3.1, s=0.55), while the traditional group, a low-calorie group that received 2/3 of their protein from animal products and 1/3 from plant products (M= 1.9, s=0.45). If sm1-M2 = 0.24, s² pooled = 0.25, nı = 8, n2 = 10 is there a difference between the two diets. Use alpha of .05 and a two-tailed test to complete the 4 steps of hypothesis testing. %D

Using a matched-group design is especially important in which of the following cases? a.  When you have only a few people in your study b.  When you have at least three levels/conditions of the independent variable c.  When you do not have a control group d.  When you have a complex dependent variable   Answer is A. But I don't understand why... could you explain? Matched-groups designs is used to address possible selection effects??but how ? and is that related to this question?

Dr. Jarry applies for a research grant to examine whether electrolyte-enriched water affects athletic performance. They propose enrolling 50 college distance runners who will consume 28 ounces of water or 28 ounces of an electrolyte-enriched solution 30 minutes before running a timed 5000 meter race. Dr. Jarry states that runners will be randomly assigned to the control group (distilled water) or the treatment group (electrolyte- enriched water). Both the electrolyte solution and the distilled water will be provided to the runners in unlabeled opaque bottles. The electrolyte solution is identical in appearance and taste to distilled water. Unfortunately, the funding agency rejects the proposal due to inadequate blinding procedures. Which of the following might have been a reason for the funding agency to reject the proposal? It is not clear whether the researcher is blinded It is not clear whether the subjects are blinded It is not clear whether either the researcher or the subjects…

In a 2009 study, a team of researchers recruited 38 men and divided them randomly into two groups - treatment or control. The also recruited 38 women and they randomly placed half the participants into the treatment group and the other half into the control group. One group was given 25 grams of chia seeds twice a day, and the other was given a placebo. The subjects volunteered to be a part of the study. After 12 weeks, the scientists found no significant difference between the groups in appetite or weight loss. Which of the following is true. (i) This is an observational study (ii) Blinding is used in this study because subjects in the control group recieved a placebo, so that htey were blinded to the treatment they recieved.  (iii) We can safely generalize the conclusion (that chia seeds have no significant effect on appetite or weight loss) from the participants to the population at large because randomization is used when assigning participatns to groups.

Suppose that as part of a research methods class, Bailey was asked to write summaries of research papers on the following topics. • The effects of increasing temperatures on the migration patterns of birds • The effects of media coverage on community support for crime prevention For each topic, identify the explanatory and the response variables. Temperature and the level of community support for crime prevention are the explanatory variables, and the amount of media coverage and the migration patterns of birds are the response variables. Temperature and the amount of media coverage are the response variables, and the migration patterns of birds and the level of community support for crime prevention are the explanatory variables. Temperature and the amount of media coverage are the explanatory variables, and the migration patterns of birds and the level of community support for crime prevention are the response variables. Temperature and the migration patterns of birds are the…

Two different blood pressure medicines are being compared to determine if the average reduction in blood pressure is the same for each medication. The goal of the study is to determine if the medications differ. Twenty men age 50-60 years old are selected for the study. Ten men are chosen at random to receive the first medication and the other 10 men receive the second medication. Each of the 20 men is monitored for one month to determine the change in blood pressure over that time. Minitab provides the 95% confidence interval for (mu1 - mu2) (2.63, 14.18) a. Interpret this 95% CI. b. What assumptions (be specific) are necessary to construct this CI?

6.34 Barking deer. Microhabitat factors associated with forage and bed sites of barking deer in Hainan Island, China were examined. In this region woods make up 4.8% of the land, cultivated grass plot makes up 14.7%, and deciduous forests make up 39.6%. Of the 426 sites where the deer forage, 4 were categorized as woods, 16 as cultivated grassplot, and 61 as deciduous forests. The table below summarizes these data.39 Woods Cultivated grassplot Deciduous forests Other Total 4 16 61 345 426 (a) Write the hypotheses for testing if barking deer prefer to forage in cer- tain habitats over others. (b) What type of test can we use to answer this research question? (c) Check if the assumptions and conditions required for this test are sat- isfied. (d) Do these data provide convincing evidence that barking deer prefer to forage in certain habitats over others? Conduct an appropriate hypoth- esis test to answer this research question. Photo by Shrikant Rao (http://flic.kr/p/4Xjdkk) CC BY 2.0…

Captivity can influence immunological responses in some mammals. Seeber et al. (2020) investigated various aspects of immunological responses in captive and free-ranging zebras. One aspect of the study involved samples of 12 free-ranging zebras from Namibia, 9 from Tanzania, and 38 captive zebras from various zoos in Europe. (All of these were non-lactating females.) One of the measured variables from blood samples was lysozyme concentration (μg/L). (Lysozyme is a biomarker of the immune response.) The researchers were interested in investigating possible differences in lysozyme concentration between zebras in the various locations.  As part of the analysis, they carried out a one-way ANOVA on the lysozyme concentrations for the zebras from the 3 locations, and found the following output.                    Df  Sum Sq    Mean Sq   F value   Pr(>F)    Location     2    50.65      25.33        42.24     6.54e-12Residuals   56   33.57      0.60  Suppose the assumptions of one-way ANOVA…