Consider the following randomized controlled experiment to study the effect of a new drug on the heart rate of healthy rats. 5 rats were randomly assigned to one of five doses and the maximum observed decrease in heart rate in one hour was recorded. The data obtained are: From this study it can be said that: Select one: a. Explanatory variable and response variable can be either of the two because the study does not specify. b. nothing can be said c. response variable is Dose and explanatory variable is (DFC) d. explanatory variable is Dose and response variable is (DFC)

The accompanying data were read from a plot (and are a subset of the complete data set) given in an article. The data represent the mean response times for a group of individuals with closed-head injury (CHI) and a matched control group without head injury on 10 different tasks. Each observation was based on a different study, and used different subjects, so it is reasonable to assume that the observations are independent. y = Study 1 2 3 4 5 6 7 8 9 10 Mean Response Time CHI 302 492 658 684 922 1044 1421 1329 1481 1815 t = Control 250 360 475 (a) Fit a linear regression model that would allow you to predict the mean response time for those suffering a closed-head injury from the mean response time on the same task for individuals with no head injury. (Round your answers to four decimal places.) 525 610 740 880 920 1010 1200 (b) Do the sample data support the hypothesis that there is a useful linear relationship between the mean response time for individuals with no head injury and the…

To examine the effect of relaxing music on math test performance, a researcher wants to compare the average math test scores of participants who completed the test with relaxing music to performance of participants who completed the same math test without music. The partially computed data collected in the study are shown below: Math Test with Music:         Math Test without Music: n1 = 16                                     n2 = 12 M1 = 82                                    M2 = 78 SS1 = 150                                 SS2 = 140 Based on these results, is there a significant effect of relaxing music on math test performance? Use a t-test for independent samples with p < .01, 2-tails to answer this research question. Follow the steps of hypothesis testing and insert your answers below. In your calculations, round all numbers to two decimal places to avoid rounding errors. ANSWER H0: H1: Computed pooled variance sp2: Estimated standard SM1 - M2: Computed t: Critical t-value for…

A researcher is interested in investigating the relationship between sugar consumption and weight gain for high school students. 15 volunteers were randomly assigned to one of two groups. The first group contained 6 volunteers who were put on a low sugar diet. The second group consisting of the remaining 9 volunteers was put on a diet with sugar constituting approximately 15% of their diet. After 8 weeks, the change in weight was recorded for each of the volunteers. Question: What is the response variable? What study principle was used in this study and what kind of study is this?

For which of the following would it be most appropriate to use an ANOVA to analyze the data?    A researcher is interested in determining the most effective format for advertising. He randomly assigns 60 people to one of three groups: (1) television commercial, (2) radio commercial, or (3) magazine advertisement. Group members review the commercial and then report whether or not they would buy the product.  In order to determine the effectiveness of different diet plans, 90 people are randomly assigned to one of three groups: (1) low calorie diet, (2) low-fat diet, or (3) low-carb diet. At the end of 60 days, the number of pounds lost was recorded for each of the participants.  Both A and B.  Neither A nor B.

st is 22. Oishi and Shigehiro (2010) report that people who move from home to home frequently as children tend to have lower than average levels of well-being as adults. To further examine this relationship, a psychologist obtains a sample of n = 12 young adults who each experienced 5 or more different homes before they were 16 years old. These participants were given a standardized well-being questionnaire for which the general population has a

The data below are from an independent-measures experiment comparing three different treatment conditions. Use an ANOVA with a = .05 to determine whether these data indicate any significant differences among the treatments    Treatment 1 Treatment 2 Treatment 3   0 1 4 N = 12 0 4 3 G = 24 0 1 6 åX2 = 92 2 0 3           M = 0.5 T = 2 M = 1.5 T = 6 M = 4 T = 16   SS = 3 SS = 9 SS = 6

The authors of a paper classified characters who were depicted smoking in movies released between a certain range of years. The smoking characters were classified according to sex and whether the character type was positive, negative, or neutral. The resulting data are summarized in the accompanying table. Assume that it is reasonable to consider this sample of smoking movie characters as representative of smoking movie characters. Do the data provide evidence an association between sex and character type for movie characters who smoke? Use α = 0.05. Sex = Male Female Positive Negative Neutral 256 Character Type 85 107 11 132 51 Calculate the test statistic. (Round your answer to two decimal places.) x² Use technology to calculate the P-value. (Round your answer to four decimal places.) P-value = What can you conclude? O Reject Ho. There is convincing evidence to conclude that there is an association between sex and character type for movie characters who smoke. Fail to reject Ho.…

Consider the following studies. Study I: A researcher randomly divided 200 high school students into two groups. The first group was told to not exercise. The second group was told to exercise at least 5 hours each week. At the end of two months, the heart rates of each participant in each group were measured at rest. It was found that the group that exercised 5 hours a week had a significantly lower average heart rate. Study II: A researcher gathered 200 high school students randomly, asked them how long they exercised each week, and then measured their heart rates at rest. It was found that students who exercised at least 5 hours a week had a significantly lower average heart rate. Part A: Which study was experimental? Why?  Study IStudy II Part B: List the explanatory and response variables in the studies.  Explanatory: heart rate; Response: exercise timeExplanatory: student; Response: amount of exerciseExplanatory: exercise time; Response: heart rate Part C: State whether the…

What are the independent and dependent variables for the following examples? What statistical test would you use for each of the following scenarios? What would you set your alpha-level at? Sally wants to examine whether there is a difference in muscular strength between participants who engaged in an 8-week resistance training program and participants who engaged in an 8-week endurance training program. The participants only took part in one of the 8-week programs, not both. What test would she use to determine whether the differences in muscular strength are significant? Why?