3. serena is the manager of the coffee shop. the amount of money she earns is represented by the equation = 21ℎ, where ℎ is the number of hours serena works, and is the amount of money she earns. how much more money does serena make an hour than gabe?

What is the distance between (–2 1/2,-3) and (1, –3)?

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

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.