PLEASE HELP!! PLEASE Jane is twice as old as Barbara. Michael is 7 years older than Jane. If Mikael is 21, which equation could be used to find Barbara's age (b)

A.2b-7=21 B.2b+7=21 C. b/2-7=21 D. b/2+7=21

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.

M the table below represents a linear function f(x) and the equation represents a function g(x): x f(x)−1 −50 −11 3g(x)g(x) = 2x − 7part a: write a sentence to compare the slope of the two functions and show the steps you used to determine the slope of f(x) and g(x). (6 points)part b: which function has a greater y-intercept? justify your answer. (4 points)

I’m still confused on how to work the percentages