A truck loaded with 8000 electronic circuit boards has just pulled into a firm's receiving dock. The supplier claims that no more than 3% of the boards fall outside the most rigid level of industry performance specifications. In a simple random sample of 300 boards from this shipment, 12 fall outside these specifications.
Construct the 95% confidence interval for the percentage of all boards in this shipment that fall outside the specifications, then comment on whether the supplier's claim would appear to be correct.