Question:The
operations manager at a compact fluorescent light bulb (CFL)
factory needs to estimate the mean...
Question
The
operations manager at a compact fluorescent light bulb (CFL)
factory needs to estimate the mean...
The
operations manager at a compact fluorescent light bulb (CFL)
factory needs to estimate the mean life of a large shipment of
CFLs. The manufacturer’s specifications are that the standard
deviation is 1,000 hours. A random sample of 64 CFLs indicated a
sample mean life of 7,500 hours.
a.
Construct a 95% confidence interval estimate for the population
mean life of compact fluorescent light bulbs in this
shipment.
b. Do
you think that the manufacturer has the right to state that the
compact fluorescent light bulbs have a mean life of 8,000 hours?
Explain.
c.
Suppose that the standard deviation changes to 800 hours. What are
your answers in (a) and (b)?