Question

10-2.25 poits As the population ages, there is increasing concern about acckdent-related injuries to the elderly. An article reported on an experiment in which the maximum lean angle-the furthest a subject is able to lean and still recover in one step-was determined for both a sample of younger females (21-29 years) and a sample of older females (67-81 years). The following observations are consistent with summary data given in the article Use the following R code to visualize the data, perform a t test and calculate the 95% CI. Data and R Code YF e 29, 34, 33, 27, 2B, 32, 31, 36, 32, 26, 28, 39, 29, 34, 33, 27, 28, 32, 31, 34) OFac( 23, 19, 22, 23, 22, 18, 14, 25, 17, 13, 21, 17) boxplot(YF, OF) t.test(YF, OF, alternative- "greater") t.test(YF, OF)sconf.int Which of the following is true based on the side by side boxplat of the data? The older females tend to have higher maximum lean angles than younger females The younger females tend to have higher maximum lean angles than older females. O The maximum lean angle is approximately the same for younger and older females Does the data suggest that true average maximum lean angle for younger females (YF) is more than it is for alder females (OF)? State and test the relevant hypotheses at significance level 0.05 by obtaining a p-value. (Use μ1 for younger females and p12 for older females.) a x1-x20 Ha: x1 x2 <0 Compute the test statistic value and find the P-value. (Round your test statistic to three decimal places and your P-value to four decimal places.) P-value State the condusion in the problem context. Reject Mo. The data suggests that true average lean angle for younger females is not more than that of older females. Fail to reject Ho. The data suggests that true average lean angle for younger females is more than that of older females. Reject Ho- The data suggests that true average lean angle for younger females is more than that of older females. Fail to reject H0. The data suggests that true average lean angle for younger females is not more than that of older females. O 参 *to . greater Based on the 95% confidence interval the average maximum lean angle for younger females is estimated to be than the average maximum lean angle older females. (Round values to 2 decimal points) You may need to use the appropriate table in the to answer this question Show Hy Work (Optional)

Answer 1

R RGui (64-bit) [R Console] R File Edit View Misc Packages Windows Help >YF-c(29,34,33,27,28,32,31,36,32,26,28,39,29,34,33,27,28,32,31,34) OF-c(23,19,22,23,22,18,14,25,17,13,21,17) YF:OF [1] 29 34 33 27 28 32 31 36 32 26 28 39 29 34 33 27 28 32 31 34 [1 23 19 22 23 22 18 14 25 17 13 21 17 >boxplot (YF,OF) > t.test (YF,OF, alternative= "greater") Welch Two Sample t-test data YF and OF t = 8.7702, df 21.324, p-value = 8.056e-09 alternative hypothesis: true difference in means is greater than o 95 percent confidence interval: 9.365841 sample estimates: Inf mean of x mean of Y 19.50 31.15 > t.test (YF,OF) $conf.int [1] 8.890086 14.409914 attr (, "conf.level") 1 0.95

R File Edit Packages Windows Help # A older females tend to have higher maximum lean angles than YF # HO: mul-mu2-0 # t value-8.7702 # P value is less than alpha. we reject H0 at alpha level . # that suggests that true difference in me ans is greater than 0 95% confidance interval is (8.890086, 14.409914)

Boxplot 寸 髦3 CN