The vertex of this parabola is at (5, -4). which of the following could be its equation?

a. y = 2(x - 5)^2 + 4

b. y = 2(x - 5)^2 - 4

c. y = 2(x + 5)^2 + 4

d. y = 2(x + 5)^2 - 4

Find the balance at the end of 4 years if 1000 is deposited at the rate of

The volume of a sphere is increased by 6%. calculate the corresponding percentage increased in it area.

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.