Scientists want to estimate the mean weight of mice after they have been fed a special diet. From previous studies, it is known that the weight is normally

distributed with standard deviation 4 grams. How many mice must be weighed so

that a 95% confidence interval will have margin of error of 0.4 grams?

Write only an integer as your answer.

Can someone me my sister? she is in third grade. 50 points and brainlist! ones that are not answered. plz and thx!

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.

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.