It is december 31st which means it is the time for you to close the books on the year refer to the balances information in the table below to answer the following questions listed under the table
dividends = $11,000
service revenue = $25,200
salary = $7,500
rent = $3,000
advertising = $2,200

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.