a researcher has a new treatment for anxiety. the researcher knows that anxiety scores are normally distributed with u = 65 and o = 12. the researcher administers their new treatment to a sample of individual and subsequently measures anxiety levels. (a) if the sample size was n = 20 and M = 60 after treatment, can the researcher conclude the new treatment has an effect? justify your response  (b) if the sample size was n = 200 and m = 63 after treatment  can the researcher conclude the new treatment has an effect? justify your response.

A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36 adults. The subjects complete a series of working memory tests before and after walking in an urban setting. Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher. The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the null and alternative hypotheses as: H00 : μDD = 0 H11 : μDD ≠ 0 Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statistics for his hypothesis test: Mean difference (MDD) 1.4 Estimated population standard deviation of the differences (s) 1.6 Estimated standard error of the mean differences (sMDMD) 0.2667 Degrees of freedom (df) 35 The t statistic 5.25 The critical values of t…

. Do patients with gastrointestinal issues experience more psychological distress than the general population?   The DASS-21 questionnaire is a validated measure of depression, anxiety, and stress. For the general population, the mean for anxiety is µ = 4.2. Anxiety levels are calculated based on self-reported answers to questions on a scale from 0 through 42, with lower scores indicating lower anxiety.   Participants with gastrointestinal issues (specifically inflammatory bowel disease, IBD) completed the DASS-21. Use the data presented below to determine whether having gastrointestinal issues like IBD significantly increases risk for anxiety. Test whether or not the performance of this sample is significantly higher than the normal population using the proper t-test.  Here are the data:   Anxiety scores: 12, 15, 10, 8, 10, 5, 10, 13, 4, 6   ANALYSES AND UNGRADED OPTIONAL GUIDING QUESTIONS: 1a. Identify the Indep.Variable:__                  Dep.Variable:__ Is it the Hypothesis…

There are many ways to measure the reading ability of children. Research designed toimprove reading performance is dependent on good measures of the outcome. Onefrequently used test is the DRP, or Degree of Reading Power. A researcher suspects that themean score µ of all third- graders in Henrico County Schools is different from the nationalmean, which is 32. To test her suspicion, she administers the DRP to an SRS of 44 HenricoCounty third-grade students. The distribution of scores is summarized in the Minitab outputbelow: MEAN STDEV SEMEAN MIN Q1 MEDIAN Q3MAXDRP 35.09 11.19 1.69 14.00 26.00 35.00 44.0054.00 Construct a 90% confidence interval to estimate the mean DRP score in Henrico CountySchools.

Scientists are interested in the placebo effect on adults with arthritis. They randomly choose 15 adults with arthritis and give them 2 treatments: effective drug and placebo for 1 week at different times. At the end of each week, the scientists ask the participants to rate their arthritic pain level on a scale of 1-5, where 1 is little pain and 5 is a lot of pain. The researchers then take the difference of their pain levels (affective drug - placebo). The data are below. 0, 1, 2, 2, 0, -1, 3, 1, 2, -1, 0, 1, -2, -1, -6 (a) Find the 5-number summary for the difference of arthritic pain levels. Minimum = Q₁ = Median = USE SALT Q3 = Maximum = (b) One of the conditions for inference for population mean difference of paired data is normality. Outliers within a data set cast a shadow of doubt upon the normality of the population distribution. Use the 5-number summary calculated in part (a) to determine if there are any outliers in the data set. Which of the values, if any, is an outlier…

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.

If you look at the differences between the means, once with 10 participants and one mean with 20 participants. (same data set) One mean difference is very large, but non-significant and the other is very small, but came out significant. What could be the reason for this outcome? (My difference in means was with 10 participants: -1.1 and with 20 participants: -5.1)

Deal with it.I need the correct answer

Ms. Long studied her students' physics test scores and sleeping habits. She found that students who slept less tended to earn lower scores on the test. What conclusion should she make?   There is no correlation between test score and amount of sleep.   There is a correlation between test score and amount of sleep. There is probably also causation. This is because there is a decrease in a student's test score with a decrease in the amount of sleep.   There is a correlation between test score and amount of sleep. There may or may not be causation. Further studies would have to be done to determine this.

The wrong alternative. One of your friends is testing the effect of drinking coffee on the duration of cold symptoms. The common cold lasts, on average, 6 days. Your friend starts with no expectations as to whether drinking coffee will have any effect on cold duration. After seeing the results of the experiment, in which the average cold duration was less than 6 days, your friend tests a one-sided alternative about the population mean cold duration when drinking coffee, H0: lcoffee = 6 На: Which gives a one-sided P value P = 0.0465. Explain why your friend should have used a two-sided hypothesis. Hcoffee < 6