Question

In an experiment to compare bearing strengths of pegs inserted in two different types of mounts, a sample of 14 observations on stress limit for red oak mounts resulted in a sample mean and sample standard deviation of 8.58 MPa and 0.77 MPa, respectively, whereas a sample of 12 observations when Douglas fir mounts were used gave a mean of 9.46 and a standard deviation of 1.52. Consider testing whether or not true average stress limits are identical for the two types of mounts. Compare df's and P-values for the unpooled and pooled t tests. in USE SALT State the appropriate hypotheses. (Use y, for the red oak mounts and Hy for the Douglas fir mounts.) Ho: H1 - H2 - 0 Ho: 41 - 420 Ho: Mi - H2 - 0 H: 4. - <0 Ho: Mi - H2 = 0 Ha: 4 - My20 Holly - H2 = 0 H:My My > 0 Calculate the degrees of freedom, test statistic and P-value using an unpooled t test. (Round your df down to the nearest whole number. Round your test statistic to one decimal place and your P-value to three decimal places.) df - 16 t = -8.0 P-value - Calculate the degrees of freedom, test statistic and p-value using a pooled t test. (Round your df down to the nearest whole number. Round your test statistic to one decimal place and your P-value to three decimal places.) df = p-value = How do the df's and P-values compare for the unpooled and pooled t tests? With the pooled method, there are --Select--- degrees of freedom, and the P-value is --Select- than with the unpooled method. If we are willing to assume equal variances, the pooled test is -Select-- capable than the unpooled test of detecting a significant difference between the sample means. You may need to use the appropriate table in the Appendix of Tables to answer this question.

Answer 1

Date: Page No mecin 1.52 are know We are given, Sample - 1 Sample size (n = 14 Sample (x) = 8.58 Sample standard deviation () = 0.77 Sample - 2 Sample mean () = 12 sample mecin () = 9.46 10 Sample standard deviation S2) не the hypothesis, Ho: el-l2 = 0 Hill, -12 + O Calculation test statistic & p-value for this TI-83184 Calculator. please go through below path. Stats → 2 - Sample T - please plug the value both the Sample then select sign for alternative hypothesis calculate - click 7 pooled : No you will got. for un pooled Fog 15 test can use Tests test for Correct 20 df 7 test statistic (+) -1.8 25 p- value 0.089 for pooled : 30 df = 24 Test Statistic (+) -1.9