I need help will rate brainliest please

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.

In the figure below, triangle rpq is similar to triangle rts. what is the distance between p and q? a. 24 b. 42 c.50 d. 54

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25