In: Statistics and Probability
Specification for a medical device calls for a mean
lifetime, of more than 160 days. The manufacturer is
investigating whether or not the lifetime of the device meets this
specification. A random sample of medical devices is selected and
their estimated lifetime using is measured, with these results (in
days): 159.7, 161.9, 164.7, 159.2, 161.3, 161.8, 162.9, 161, 158.5,
161.2.
A normal probability plot looks reasonably straight. We will assume
that these lifetimes are normally distributed. Consider a
significance level α=0.05.
The critical value is:
Solution-
Test results that the null hypothesis is rejected.
So ,there is enough evidence to claim that Specification for a medical device calls for a mean lifetime is more than 160 days