Your friend asks you to her babysit and will pay you 3 pennies for the first job. you agree to if she triples your payment for each job completed. after 2 jobs, you will receive 9 pennies, and after 3 babysitting jobs, you will receive 27 pennies. complete and solve the equation that finds the number of pennies she will pay you after the 9th babysitting job.

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.