Can I get help with these?
Consider the following output from R's t.test procedure, involving a two-sample problem where each group had the same sample size. Two Sample t-test data: Group1 and Group2 t - -1.3577, df - 198, p-value = 0.1761 alternative hypothesis: true difference in means is not equal to O 95 percent confidence interval: -0.45235768 0.08346348 sample estimates: mean of x mean of y -0.15127452 0.03317258 Which of the following statements are true? There may be more than one correct statement; check all that are true. )a) One way to express the null hypothesis used in this test isHo : X1 = X2. b) Each group had 100 observations. )c) The confidence interval given in the output implies that the true mean of each group is O. d) The evidence against the null hypothesis is statistically significant at the 10% significance level.Which of the following statements about two-sample inference procedures are true? There may be more than one correct statement; check all that are true. a) The Welch t procedure and pooled-variance t procedure both assume the sample means are equal. b) The pooled-variance t procedure only works if the sample size is very large. c) The Welch t procedure and pooled-variance t procedure both require equal sample sizes. (d) If the population variances are known to be equal, then the pooled-variance t procedure is a better choice than the Welch procedure.Researchers wished to investigate the possible effect of grapefruit consumption on blood pressure. In an experiment, each of 200 volunteers was randomly assigned to either a grapefruit group or a control group (100 to each group). The grapefruit group had the same diet as the control group, with the addition of a single grapefruit per day. After 6 weeks, reduction in systolic blood pressure was recorded. On average, the grapefruit group's systolic blood pressure was reduced by 3.1 mm Hg, whereas the control group's reduced by 0.2 mm Hg. The researchers used the pooled-variance t procedure to test the null hypothesis that the true mean reduction was the same for both groups, against a two-sided alternative, and found a p-value of 0.008. Of the following options, which one is the best conclusion to that hypothesis test? There is very strong evidence that grapefruit consumption tends to reduce systolic blood pressure (under the conditions of this experiment). O There is no evidence of a difference in mean systolic blood pressure reduction between the two groups. There is very strong evidence that the sample mean reduction for the grapefruit group is greater than the sample mean reduction for the control group. There is no evidence that grapefruit consumption tends to reduce systolic blood pressure (under the conditions of this experiment)