An industrial supplier has shipped a truckload of teflon
lubricant cartridges to an aerospace customer. The customer has
been assured that the mean weight of these cartridges is in excess
of the 15 ounces printed on each cartridge. To check
this claim, a sample of n=20 cartridges are
randomly selected from the shipment and carefully weighed. Summary
statistics for the sample are: x equals 15.16
ounces, s =0.30 ounce. To determine whether
the supplier's claim is true, consider
the test,
H0: μ= 15 vs. Ha: μ>15, where μ is
the true mean weight of the cartridges. Find the rejection region
for the test using .α=0.01.
A. t >2.861, where t depends
on 19 df
B.t >2.539, where t depends on 19 df
C. |z|>2.58
D. z >2.33