Explain the circumstances under which we would need to pool the variance for an independent samples t-test

A researcher was interested in knowing if mean BMI was different between males and females. He obtained the following test results. Choose the correct interpretation of the results: F test p value = 0.03 Two sample t test, assume equal variance = 0.02 Two sample t test, assume unequal variance = 0.06 Mean BMI is higher in males than females. None Mean BMI is not significantly different between males and females. Mean BMI is significantly different between males and females.

Post-hoc tests are necessary for an analysis of variance comparing only two treatment conditions.  t or f

Which of the following conclusions is correct for these test results? > bartlett.test(len~river, data=rivers) Bartlett test of homogeneity of variances data: len by river Bartlett's K-squared = 0.61394, df = 4, p-value = 0.5226 %3D Hint* the first line of code should tell you the type of test you are dealing with. There is NO significant difference in variances among the rivers. There is a significant difference in variances among the rivers. There is NO significant difference in means among the rivers.

A researcher is interested whether a new drug is effective in changing patients' cholesterol levels. She divided 33 patients into 3 groups according to the dosage the patient received. The cholesterol levels of all patients are measured and used as the data for the Analysis of Variance (ANOVA). If she reported the test statistic F = 2.1 What is the degree of freedom for the numerator of the F statistic? What is the degree of freedom for the denominator of the F statistic? What is the P-value of the F-test? (Round to 3 decimals) Given the significance level of 0.01, what can she conclude from the test? *The patients in differnt groups have simliar average cholesterial levels. The drug made no difference. *At least one group of patients have an average cholesterol level that is different from the other groups. The drug may have an effect.

What correctly represents the coefficient of determination in terms of the variance that is an output from the analysis of variance table?

A researcher wants to measure average cardiovascular health of university students and compare those scores to the average scores in the general population. Assuming that population variance is known, what statistical test is most appropriate for this study?        independent-samples t-test     single-sample t-test     z-test for sample mean     related-samples t-test

Hi there, I am having a difficult time synthesizing this information I obtained from excel. I compiled the data utilizing a two-sample t-Test assuming equal variances.  1. Who is most likely to have prevalent coronary heart disease? Test if there are significant differences in the following risk factors between persons with and without prevalent coronary heart disease (CHD). Summarize the statistical results in the table below and then compare risk factors in persons with and without prevalent CHD.    Patient Characteristic* History of CHD (n = 194) No History of CHD (n = 4240) p-value* Age, years 57.48 (7.42) 49.58 (8.57) < 0.001 Systolic blood pressure, mmHg 145.00 (27.03) 132.35 (22.03) < 0.001 Diastolic blood pressure, mmHg 87.14 (14.33) 82.90 (11.91) < 0.001 Total serum cholesterol, mg/dL 243.20 (45.61) 236.70 (44.59) 0.049 Body mass index 26.83 (4.45) 25.80 (4.08) < 0.001 * Mean (Standard deviation).…