Independent random samples from normal populations produced the results shown in the table to the right. Complete parts a through d below. Sample 1 Sample 21.2 3.31.7 3.62.3 2.81.6 3.81.9 a. Calculate the polled esimate of σ². b. Do the data provide sufficient evidence to indicate that U2 > U1? Test using α= .1 What are the null and alternative hypotheses? What is the test statistic? t= (round to two decimal places as needed) What is the observed significance level? p-value= (round to three decimal places as needed) c. Find a 90% confidence interval for (U1 - U2) d. Which of the two inferential procedures, the test of hypothesis in part b or the confidenve interval in part c, provides more information about (U1 - U2)?