When we will form confidence intervals for difference between population standard deviations.
Then we would observe the confidence interval
1) if confidence interval contain 0 (e.g. (-3,2)), then we conclude that the no difference between population standard deviations.
2) if confidence interval does not contain 0 (e.g. (2,5) or (-4,-2), then we conclude that the their is difference between population standard deviations.
a) if confidence interval does not contain 0 and contain positive value (e.g. (1,5) ), then we can conclude that standard deviations for population 1 is greater than that of for population 2.
b) if confidence interval does not contain 0 and contain negative value (e.g. (-1,-5) ), then we can conclude that standard deviations for population 1 is less than that of for population 2.
What specifically should one be looking for with respect to the test intervals when analyzing possible differences between two population standard deviations using the notion of confidence intervals....
When the standard deviations are equal but unknown, a test for the differences between two population means has n − 1 degrees of freedom. True or False?
When the standard deviations are equal but unknown, a test for the differences between two population means has n − 1 degrees of freedom. True or False
Which one of the following is true for confidence intervals for the difference between two population meansμ1−μ2? (a) The 90% confidence interval is wider than the 95% confidence interval. (b) The 95% confidence interval is wider than the 90% confidence interval. (c) The 90% and 95% confidence intervals have the same width.
please solve the example As with the confidence intervals, we will be assuming the two population standard deviations are equa but unknown. Thus, we will need to calculate the pooled standard deviation to use in our test statistic. Dur typical hypothesis test would be of the form H:44-42 = 8vs. H:4,-4, 78This is a two side test because the alternative is not equal. (H:14-4, <8, or H:44 - H2>, are also possible. Our test statistic is I X - X₂-8...
Subject: Hypothesis test of a standard deviation (one population) and two standard deviations (two populations). Instructions: Present the manual calculations of (1) statistical tests and (2) confidence intervals, the populations are low season and high season. Times of Lane C (in Total time (A+B+C in Times of Lane A (in seconds) seconds) 478 202 Times of Lane B (in seconds) seconds) 359 439 312 594 709 515 480 325 218 311 404 325 306 205 540 193 284 448 283...
6) When ANOVA F-test suggests that the population means differ, we can examine confidence intervals estimating each population mean to try to determine which population means account for the difference. These are the same one-sample T- intervals we learned in Unit 9. The fictitious data from Study #2 give these 95% confidence intervals. Which population means appear to differ? Which might be the same? Table of confidence interval calculation 1 Grade Sample Mean Std. Err. DF L. Limit U. Limit...
Is there a relationship between confidence intervals and two-tailed hypothesis tests? Let c be the level of confidence used to construct a confidence interval from sample data. Let α be the level of significance for a two-tailed hypothesis test. The following statement applies to hypothesis tests of the mean. For a two-tailed hypothesis test with level of significance α and null hypothesis H0: μ = k, we reject H0 whenever k falls outside the c = 1 − α confidence...
* (½ point) The Pearson Chi-square test is used to test hypotheses about what? Differences in proportions between two groups Differences in proportions between more than two groups Association between two categorical variables All of the above * (½ point) The paired t test is used to test hypotheses about what? Differences in proportions between two groups Differences in means between individuals Means of differences within individuals All of the above * (½ point) If one performs four hypothesis tests...
Test: Chapter 6 Confidence Intervals Submit Test This Question: 1 pt 16 of 20 (4 complete) This Test: 20 pts possible Use the standard normal distribution or the t-distribution to construct a 95 % confidence interval for the population mean. Justify your decision. If neither distribution can e used, explain why. Interpret the results. ning backs are shown below. Assume the yards per carry are normall per carry for In a re t season, the ulation standard eviation of the...
Considering the differences between a one-tailed and two-tailed independent samples t-test, using the same data set, which of the following is NOT true: A. the calculated t statistic will be the same for both B. an F-test of variances is required in both cases C. the d.f. will be the same for both tests D. we should select different values for these tests