## Statistics (12th Edition)

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: $\bar d - E = 3.3 - 0.4431 = 2.8569$ $\bar d - E = 3.3 + 0.4431 = 3.7431$