An Injector Molder Produces Plastic Pens

Multiple Choice

An injector molder produces plastic pens.The process is designed to produce pens with a mean weight of 0.250 grams.To investigate whether the injection molder is operating satisfactorily,40 pens were randomly sample with a mean of 0.2525g.The population standard deviation is believed to be approximately 0.0022g.Find a 99% confidence interval for the population mean.

A) [.2514;2536]
B) [.2516;534]
C) [.2517;2533]
D) [.2518;2532]
E) [.2521;2529]