Question

Which type of error is used to compute the confidence interval for two related samples selected from at least one population with an unknown variance?

                      A)    standard error

                      B)    estimated standard error

                      C)    estimated standard error for the difference

                      D)    estimated standard error for the difference scores

Answer 1

Answer is

D) estimated standard error for the difference scores

Note : The confidence interval for mean difference is

where

is mean of difference in sample score

di is the difference in sample scores, that is di = xi-yi  

(xi , yi ) is the paired observation of ith subject  

and is the standard error for the difference in sample scores

which is the estimated standard error of the difference in sample scores