Give a geometric description of the set of points in space whose coordinates satisfy the given pair of equations. x2 + y2= 16, z = 2
Choose the correct description.
A. The circle with center (0, 0, 2) and radius 4, parallel to the xy-plane
B. The line through (4, 4, 2), parallel to the z-axis
C. The line that passes through the points (4, 0, 2) and (0, 4, 2)
D. The circle with center (4, 4, 0) and radius 2, parallel to the xy-plane

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

Can someone pls ! pls answer all. no explanation needed..

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.