Assuming that both populations are normally distributed cons

Assuming that both populations are normally distributed, construct a 90% confidence interval about Mu1-Mu2.(Mu1 represents the mean of the experimental group and Mu2 represents the mean of the control group.) The confidence interval has a lower bound of and an upper bound of. (Use ascending order. Round to two decimal places as needed.)

Solution

Answer

Confidence interval =| x1-x2|- (table value) sqrt( S²(1/n1+1/n2)) and |x1-x2|+(table value) sqrt( S²?(1/n1+1/n2)) where S²=(n1(s1)²n2(s2)²⁾/(n1+n2-2)

=|45.8-49.6|-1.313(3.1875) and |45.8-49.6|+1.313(3.1875) (table value of t at 10% for n1+n2-2 degrees of freedom =22+18-2=38 is 1.313)

  lower bound = -0.39 and upper bound =7.99