Answer
0.5156 to 3.484
Work Step by Step
df = n - 1 = 6 - 1 = 5
$t_{α/2} = 0.025$
From student's t distribution table, we have:
$t_{0.025} = 2.571$
$E = 2.571 . \frac{\sqrt 2}{\sqrt 6} = 2.571 . 0.577 = 1.484$
Confidence interval will be:
$\bar d - E = 2 - 1.484 = 0.5156$
$\bar d - E = 2 + 1.484 = 3.484$