A researcher questions whether there is a correlation between the initial math-related anxiety and the final grade of the statistics course.  She computes the Pearson's r in a class of 37 students and gets a value or r = .324.  What should her statistical decision be at the alpha = .05 level?   a. She should fail to reject the null hypothesis if this was either one-tailed or two-tailed test.   b. She should fail to reject the null hypothesis if this was a one-tailed test but not if it was a two-tailed test.   c. She should reject the null hypothesis if this was either a one-tailed or two-tailed test.   d. She should reject the null hypothesis if this was a one-tailed test but not if it was a two-tailed test.

Under what circumstances is a t statistic used instead of a z-score for a hypothesis test?     Justin wants to know whether a commonly prescribed drug does improve the attention span of students with attention deficit disorder (ADD). He knows that the mean attention span for students with ADD who are not taking the drug is 2.3 minutes long. His sample of 12 students taking the drug yielded a mean of 4.6 minutes. Justin can find no information regarding σx , so he calculated s2x =1.96. Identify the independent and dependent variables. In a sentence, state the null hypothesis being tested. c. Using symbols, state the null and alternative hypotheses

A physical therapist wanted to know whether the mean step pulse of men was less than the mean step pulse of women. She randomly selected 52 men and 73 women to participate in the study. Each subject was required to step up and down a 6-inch platform. The pulse of each subject was then recorded. The following results were obtained. (a) State the null and alternative hypotheses. Which of the following is correct? OC. Hgi H1 =H2i H H2 (b) Identify the P-value and state the researcher's conclusion if the level of significance was a = 0.02. What is the P-value? P.value =

Last week Jenni had exams in Spanish and in Cognition. She scored 5 points above the mean on both exams. From this information, what can you conclude about the z-scores for Jenni’s two scores? a. Jenni will have a higher z-score for the exam with the lower mean. b. None of the other choices is correct. c. Jenni has identical z-scores for the two exams. d. Both of Jenni's z-scores are positive.

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…

10.In a study we reject Ho Which of the following statements are incorrect and why? (a) "Now we know that H, is false." (b) "We have proof that our sample mean represents a particular p." (c) "We have proof that the independent variable causes scores to change as predicted." (d) "It is not pos- sible that the difference between X and u is due to sampling error." (e) "We have evidence that the predicted relationship does

It is assumed that standardized test scores should be correlated with students' classroom performance. One would expect that students who consistently perform well in the classroom (on tests, quizzes, etc.) would also perform well on a standardized test scored from 0-100 (with 100 indicating high achievement). A teacher decides to examine this hypothesis. At the end of the academic year, she collects the following data for her (admittedly small) class: Standardized test score Overall GPA 56 1.8 1 73 2.6 2 78 2.9 3 83 2.9 4 85 3.0 5 rows x 2 columns What is your best guess for the expected GPA of a student who scored a 88 on the standardized test? number (rtol=0.01, atol=0.0001) Determine a 95% confidence interval for the expected GPA of a student who scored a 76 on the standardized test. Ib number (rtol=0.01, atol=0.0001) ub number (rtol=0.01, atol=0.0001)

#2...Can you write out answer please n thank u

Casey is a statistics student who is conducting a one-sample ?z‑test for a population proportion ?p using a significance level of ?=0.05α=0.05. Her null (?0H0) and alternative (??Ha) hypotheses are ?0:???:?=0.094≠0.094H0:p=0.094Ha:p≠0.094   The standardized test statistic is ?z = 1.20. What is the ?P-value of the test?

Under what circumstances is a t statistic used instead of a z-score for a hypothesis test?     Justin wants to know whether a commonly prescribed drug does improve the attention span of students with attention deficit disorder (ADD). He knows that the mean attention span for students with ADD who are not taking the drug is 2.3 minutes long. His sample of 12 students taking the drug yielded a mean of 4.6 minutes. Justin can find no information regarding σx , so he calculated s2x =1.96. Determine the critical region using a one-tailed test with alpha = .05. Conduct the hypothesis test (Do the math and compare the t-critical and t-obtained values). State your conclusions in terms of H0 (Should you reject the H0 or fail to reject/accept the H0). Based on your analysis, is there a relationship between the drug and attention span?