#### Answer

For 1-c/2 = 0.495, using standard normal table, we have:
z = 2.575
$E = 2.575 . \frac{1.5}{\sqrt 76} = 2.575 . 0.172 = 0.4431$
Confidence interval will be:
$\bar d - E = 3.3 - 0.4431 = 2.8569$
$\bar d - E = 3.3 + 0.4431 = 3.7431$

#### Work Step by Step

As above