On Friday 80% of the costumers who bought tickets at a movie theater also bought popcorn. There were 320 costumers who bought tickets at the movie theater. How many of these 320 costumers also bought popcorn?

Is it true that product of 3 consecutive natural numbers is always divisible by 6? justifyyour answer

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.

Anne plans to increase the prices of all the items in her store by 5%. to the nearest cent, how much will an artist save if the artist buys a canvas and a frame that each measure 24 by 36 inches before the price increase goes into effect?