Which number sentence below matches this word problem? there are 6 days until richard's concert. susie's concert is 7 days after richard's. how many days are there until susie's concert? a.6 + 7 = 13 b.13 - 6 = 7 c.7 × 6 = 42 d.42 6 = 7

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

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.