Pls me with 19,20 pls thx and show me how u did it

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package

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.