At the 5 significance level does the evidence suggest that t

At the 5% significance level, does the evidence suggest that the top of the line bat does increase the average distance hit versus the lower price bat? Do you think there is a confounding factor that was not controlled for in the design of the experiment? Does owning an indoor dog really help bring down borderline high systolic blood pressure? To answer this question, a random sample of twelve subjects with chronically borderline high systolic blood pressure was obtained. Their systolic blood pressure was recorded. They then received a house-trained dog to live indoor with them. After one month, their blood pressure was taken again. At the 2.5% significance level, can you conclude that owning a pet will reduce the average systolic blood pressure? A popular myth is that for identical twins, one is the \"nice one\" and one is the \"mean one. \"Fourteen pairs of identical twins were randomly selected and given a personality test for measuring \"niceness\" or \"meanness\" where the higher score implies \"niceness\" and a lower score implies \"meanness \" At the 1% significance level, is there a difference in the personality scores between the identical twins.

Solution

so, difference in blood pressure = ( blood pressure before - blood pressure after)...

so, H0 : difference in blood pressure = 0 ag. H1 : difference in blood pressure > 0....

d = difference in blood pressure!

d-bar = mean of difference = mean of blodd pressure before - mean of blood pressure after

= 128.867 - 130.125 = -1.258
s_d = sqrt [ ((d_i - d-bar)² / (n - 1) ] = 2.795925
and std. error= ( s.d / sqrt ( n) ) = 0.807.....

so, test statistic = d-bar / std. error = - 1.258 / 0.807 = -1.5590527.......

p-value = 0.07364..which is greater than 0.025 = level of significance!

Hence , we fail to reject H0 and conclud ethat there is not enough evidence to support that blood pressure is getting reduced!!