Do people feel hungrier after sampling a healthy food? The authors of a consumer research paper carried out a study to answer this question. They randomly assigned volunteers into one of three groups. The people in the first group were asked to taste a snack that was billed as a new health bar containing high levels of protein, vitamins, and fiber. The people in the second group were asked to taste the same snack but were told it was a tasty chocolate bar with a raspberry center. After tasting the snack, participants were asked to rate their hunger level on a scale from 1 (not at all hungry) to 7 (very hungry). The people in the third group were asked to rate their hunger but were not given a snack. The data in the table are consistent with summary quantities given in the paper (although the sample sizes in the actual study were larger). Treatment Group Hunger Rating Sample Mean Sample Standard Deviation Healthy 5 7 7 4 7 3 4 7 6 5.6 1.59 Tasty 4 1 5 2 6 2 5 3 4 3.6 1.67 No Snack 3 4 5 6 5 5 2 4 4 4.2 1.20 Overall mean = 4.4 (a) Do these data provide evidence that the mean hunger rating differs for at least two of the treatments ("healthy" snack, "tasty" snack, no snack)? Test the relevant hypotheses using a significance level of 0.05. State the appropriate null and alternative hypotheses. (Let M1, M2, and 3 be the true means for the three different treatments.) Ho at least two of the three μ's are different Ha H₁ =H2 H3 : O Ho H1 H2 H3 Ha at least two of the three μ's are different Ho H₁ =H2 H3 Ha all three of the μ's are different different

Do people feel hungrier after sampling a healthy food? The authors of a consumer research paper carried out a study to answer this question. They randomly assigned volunteers into one of three groups. The people in the first group were asked to taste a snack that was described as a new health bar containing high levels of protein, vitamins, and fiber. The people in the second group were asked to taste the same snack but were told it was a tasty chocolate bar with a raspberry center. After tasting the snack, participants were asked to rate their hunger level on a scale from 1 (not at all hungry) to 7 (very hungry). The people in the third group were asked to rate their hunger but were not given a snack. The data in the table are consistent with summary quantities given in the paper (although the sample sizes in the actual study were larger). TreatmentGroup Hunger Rating SampleMean SampleStandardDeviation Healthy 5 8 7 4 7 3 4 7 6 5.6667 1.7321 Tasty 4 1 5 2 6 2 5 3 4 3.5556…

A clinical psychologist wants to test the effectiveness of three new therapies that have been developed for reducing anxiety symptoms. The researcher recruits 15 participants and randomly assigns them to take part in Therapy A, Therapy B, or Therapy C for a month. At the end of the month, the researcher measures the participants' anxiety symptoms on a scale from 1 to 10 (where a higher score means more anxiety symptoms). The participants' scores are shown below: What is the appropriate test to use ? 3. What are the null and alternative hypotheses ? 4. Using a two-tailed alpha of .05, determine what the critical value is 5. Calculate the test statistic 6. State whether you reject or fail to reject the null hypothesis for the omnibus test 7. Calculate and report the effect size for the omnibus test 8. Perform a Post-Hoc Test. Report the significance of each pairwise comparison

A researcher conducts an independent-measures study to examine how the brain chemical serotonin is related to aggression.  One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin.  A second sample of rats, low serotonin group, receives a drug that lowers brain levels of serotonin.  Then, the researcher tests the animals by recording the number of aggressive responses each of the rats display.  See the data below. Is there a significant difference between the control group and the low serotonin group regarding the number of aggressive responses?                                                Control         Low Serotonin                                                    n = 10                 n = 15                                                M = 14               M = 19                                                SS = 180.5         SS = 130 Perform a hypothesis test using independent-measures t-test. Use a two-tailed…

A randomly sampled group of patients at a major U.S. regional hospital became part of a nutrition study on dietary habits. Part of the study consisted of a 50-question survey asking about types of foods consumed. Each question was scored on a scale from one (most unhealthy behavior) to five (most healthy behavior). The answers were summed and averaged. The population of interest is the patients at the regional hospital. The current survey was implemented after patients were subjected to this education, and it produced the following sample statistics for 25 patients sampled:  and s = 1.02. We would like to know if the education improved nutrition behavior. We test the hypotheses H 0:  = 2.9 versus Ha:  > 2.9. The value of the t test is 1.96, and:   a. P-value > 0.1.   b. 0.025  P-value < 0.05.   c. 0.25  P-value < 0.01.   d. 0.05  P-value < 0.1.   Given the least squares regression line y = 3 x – 3, which of the following is true?   a. The…

Does the shape or color of a pain pill influence its effectiveness?  Although logically it shouldn’t, whether we believe a drug will work does have a powerful effect on our perceptions (e.g., placebo effect).  In this experiment, 4 groups of adult patients were given the same amount of Advil after dental surgery for pain relief, but the color and shape of the pill varied.  Researchers hypothesized that an unusual shape or color would lead people to believe the pills were new and special and thus would expect them to be more effective than common round, white pills. Researchers also wanted to know if there is an interaction between shape and color   what is the purpose and design of the study as well as the characteristics of the participants in the sample?

A psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below. Group A 67 93 82 69 76 47 43 58 92 63 52   Group B 70 57 75 59 66 49 55 46 45 91 89 72 Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch. (a) What is the level of significance? (b) Compute the sample test statistic. (Use 2 decimal places.) (c) Find the P-value of the sample test statistic. (Use 4 decimal places.)

A researcher conducts an independent-measures study to examine how the brain chemical serotonin is related to aggression.  One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin.  A second sample of rats, low serotonin group, receives a drug that lowers brain levels of serotonin.  Then, the researcher tests the animals by recording the number of aggressive responses each of the rats display.  See the data below. Is there a significant difference between the control group and the low serotonin group regarding the number of aggressive responses?                                                Control         Low Serotonin                                                    n = 10                 n = 15                                                M = 14               M = 19                                                SS = 180.5         SS = 130 Perform a hypothesis test using independent-measures t-test. Use a two-tailed…

A recent study investigated whether cell phone users experience separation anxiety when they cannot access their phones. Because blood pressure increases with anxiety, the researchers used systolic blood pressure as an operational measure of anxiety. The experiment involved a random sample of cell phone users that were divided into two groups at random. One group of participants completed a survey while their phones were locked in a cabinet in a separate room and the other group of participants completed the same survey while their phones were nearby. (The survey questions were unrelated to cell phone use.) At the end of the survey, theresearchers measured each participant's systolic blood pressure. The same experiment was conducted in Montreal, Toronto, Vancouver, and St. Zotique. The blood pressure data needed is below. Use these data to answer the following question: compute r2 for the data collected in st. zotique. Please answer to 5 decimal places. Cell Phone (CP) No Cell Phone…

A research group conducted an extensive survey of 2940 wage and salaried workers on issues ranging from relationships with their bosses to household chores. The data were gathered through hour-long telephone interviews with a nationally representative sample. In response to the question, "What does success mean to you?" 1470 responded, "Personal satisfaction from doing a good job." Let p be the population proportion of all wage and salaried workers who would respond the same way to the stated question. How large a sample is needed if we wish to be 95% confident that the sample percentage of those equating success with personal satisfaction is within 1.6% of the population percentage? (Hint: Use p ≈ 0.50 as a preliminary estimate. Round your answer up to the nearest whole number.) workers