An anger-management courseclaims that, after completing its seminar, participants will lose their tempers less often. Always a skeptic, you decide to test this claim. A random sample of 12 seminar participants is chosen, and these participants are asked to record the number of times that they lost their tempers in the two weeks prior to the course. After the course is over, the same participants are asked to record the number of times that they lost their tempers in the next two weeks. The following table lists the results of the survey. Using these data, test the claim at the 0.01 level of significance assuming that the population distribution of the paired differences is approximately normal. Let d= (participants after completing the anger-management course) −(participants before completing the anger-management course).  Number of Times Temper Was Lost during a Two-Week Period Before 10 6 5 8 7 7 10 6 3 10 3 8 After 6 7 4 5 4 7 8 6 4 9 3 7  Step 2 of 3 :  Compute the value of the test statistic. Round your answer to three decimal places.

A researcher wants to conduct an experiment to determine which environment is best suited for studying - a library, in one's own room, or outside. A total of 30 university students volunteer to participate in the experiment. The researcher believes that gender has an effect on the results. What are the treatments in the experiment?

A psychologist would like to examine the effects of a new drug on the activity level of animals. Three samples of rats are selected with n=5 in each sample. One group gets no drug, one group gets s small dose, and the third group gets a large dose. The psychologist records the activity level for each animal. The data from this experiment are presented below.   No drug Small dose Large dose 5, 3 , 1 , 1 , 5 5, 5, 9, 6, 5 10, 12, 9, 6, 8 =3, SS=16 =6, SS=12 =9, SS=20   Do these data indicate any significant differences among the three groups? Test with α=0.05.                        Compute the effect size and interpret the result.

A researcher designs an intervention to combat anti-Arab oppression. She also designs a questionnaire to measure anti-Arab oppression so she can test the participants' level of anti-Arab oppression before and after the intervention. She tests one version of her questionnaire with 45 statements and a shorter version with 12 statements. In both questionnaires, the participants respond to each statement with a rating on a 5-point Likert scale with 0 equaling "strongly disagree" and 4 equaling "strongly agree." The overall score for each participant is the mean of his or her ratings for the different statements on the questionnaire. Look at the following graphs. Graph I graphs the results from the long version, and Graph II graphs the results from the short version. Graph I Graph II PARTICIPANTS PARTICIPANTS 8 8 7 7 6 6 4 4 3 3 2 1 1 1 2 3 4 2 4 LONG QUESTIONNAIRE SCORE SHORT QUESTIONNAIRE SCORE Complete the following sentences by trusting your eyes to see meaningful differences in the two…

Suppose you are the manager of two beachfront hotels : The Palms and Golden Sands. You'd like to know if there is a difference in guest satisfaction between the two hotels. To investigate this, you conduct a survey and ask guests upon departure if they are likely to return to the hotel in the future. For The Palms, 163 out of 227 guests who were surveyed responded " yes ". For Golden Sands, 154 out of 262 guests responded "yes ". Answer the following questions. Round any numbers in your final answers to 2 decimals. 1) Calculate a 95 % confidence interval for the difference in satisfaction rates between The Palms and Golden Sands (Show work) 2) Use the critical value approach to test, at a 1% significance level, whether or not the guest satisfaction rates are different between the two hotels. What do you conclude ? (In your answer, show the steps involved with testing) 3) What is the p-value of your test in part 2?

Several friends charted a boat for a day's fishing. They caught a total of 51 fish. The table below provides information about the type and number of fish caught. determine the empirical probablity that the next fish caught is a flounder. Grouper - 15 Shark - 17 Flounder - 8 Kingfish - 11

A high school track coach wanted to test whether giving the students an energy drink could affect performance during the 100 meter race. The coach split the 26 boys into two equal sized groups, where Group 1 was given the energy drink and Group 2 was not. The 100 meter race times were recorded during practice and shown in the table below. What inference can be made about the results? Group 1 Group 2 12.2 13 12.5 12.3 13.3 12.8 12.9 13 13 13.8 12.1 13 13 13 13 13 12.1 13 13 13 12.1 13 12.8 13 13 12.6     Mean: 12.7 Mean: 13   Since the simulation shows ( many cases or free cases )?  where a mean  difference of ( solve for this answer )   or less occurred when the groups were re-randomized, it can be inferred that the mean difference observed in the study was ( very possibly or very unlikely )  ?due to the random assignment of participants into groups, so the results of the study are (…

Maddie conducts a study to see if listening to music helps students learn math.  She surveys a random sample of 250 college sophomores who completed a math class within the past six months.  She asks them to indicate how frequently they listened to music while studying math.  The students also report their final grade in the math class at the end of the semester.   Select the statement below that is false.     There is no placebo in this study.     Maddie conducted an observational study.     A confounding variable could be how often the participants studied math.     The population Maddie studied was 250 college sophomores.

A psychologist conducted a survey of the attitude towards the sustainability of American energy consumption with 250250 randomly selected individuals several years ago. The psychologist believes that these attitudes have changed over time. To test this he randomly selects 250250 individuals and asks them the same questions. Can the psychologist confirm his theory that the attitudes have changed from the first survey to the second survey? Attitude 1st Survey 2nd Survey Optimistic 50%50% 52%52% Slightly Optimistic 16%16% 10%10% Slightly Pessimistic 11%11% 15%15% Pessimistic 23%23% 23%23% Copy Data Step 6 of 10 :   Find the value of the test statistic. Round your answer to three decimal places. Step 7 of 10: Find the degrees of freedom associated with the test statistic for this problem Step 8 of 10: Find the critical value of the test at the 0.025 level of significance. Round your answer to three decimal places.step 9 of 10: make the decision to reject or fail to reject…

During the first few weeks of the new television season, the evening news audience proportions were recorded as ABC - 31%, CBS - 34%, and NBC - 35%. A sample of 800 homes taken recently yielded the following viewing audience data.   Number of Homes ABC 305 CBS 255 NBC 240 ​ We want to determine whether or not there has been a significant change in the proportion of viewing audience of the three networks. a. State the null and alternative hypotheses to be tested. b. Compute the expected frequencies. c. Compute the test statistic. d. Determine the p-value for this test. Make a conclusion in the context of this problem