Answer:
The 95% confidence interval for the proportion of all boards in this shipment that fall outside the specification is (1.8%, 6.2%).
Step-by-step explanation:
Let <em>X</em> = number of boards that fall outside the most rigid level of industry performance specifications.
In a random sample of 300 boards the number of defective boards was 12.
Compute the sample proportion of defective boards as follows:

The (1 - <em>α</em>)% confidence interval for population proportion <em>p</em> is:

The critical value of <em>z</em> for 95% confidence level is,

*Use a <em>z</em>-table.
Compute the 95% confidence interval for the proportion of all boards in this shipment that fall outside the specification as follows:

Thus, the 95% confidence interval for the proportion of all boards in this shipment that fall outside the specification is (1.8%, 6.2%).
Umm this might be wrong, but i think you have do the inverse, which would make -4 positive, then add that to the 2, and then subtract that from 0.6 and then whatever you answer you get is equal to the variable z.
Answer:
197in^2
Step-by-step explanation:
5x5=25(top face)
5x5=25(left face)
9x5=45(bottom face)
6.4x5=26(right face)
Front and behind face: trapezoid area (trapezoid formula h x (a+b)/2)
(5+9)/2 x 5=7x5=35
35+35+25+25+45+25=197in^2