Jack had 3bags of golf balls with b balls in each bag; then his friend gave him 6 more golf balls. How many golf balls does Jack have now?

What is the most accurate measurement of 1 pound

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.

Someone me! if you’re smart you can solve this!