In this study 100 groups of five participants were used to discover problems with an interface. The study did indeed find that the mean percentage of problems discovered across all 100 groups was about 85%. However, this figure has 95% confidence level and a margin of error of Â±18.5%.
Keelboats were generally built in Pittsburgh, Pennsylvania and it was here that Meriwether Lewis commissioned the boat used by the Corps of Discovery. The keelboat used by the Corps was sketched by Clark in his journal. It was 55 feet long and 8 feet wide, with a 3- to 4-foot draft. For propulsion it had a 32-foot sailing mast, 22 oars, a rudder, and a tiller for steering. Protection against hostile encounters were a swivel cannon on the bow and two smaller guns called blunderbusses.
The minimum length of the opening on a C1 is 280 cm (110 in). Boats are long and streamlined with a narrow beam, which makes them very unstable. A C4 can be up to 9 m (30 ft) long and weigh 30 kg (66 lb). ICF classes include C1 (solo), C2 (crew of two), and C4 (crew of four).he minimum length of the opening on a C1 is 280 cm (110 in). Boats are long and streamlined with a narrow beam, which makes them very unstable. A C4 can be up to 9 m (30 ft) long and weigh 30 kg (66 lb). ICF classes include C1 (solo), C2 (crew of two), and C4 (crew of four).