Edalight is a manufacturer of compact fluorescent lights (CFL) bulbs which are fluorescent bulbs designed to be more efficient than traditional incandescent bulbs. In an effort to produce a consistent product, suppose Edalight has a goal that the standard deviation for the life of its CFL bulbs is less than 500 hours. The standard deviation for the life of a random sample of 28 CFL bulbs was found to be 378 hours.
a. Using α = 0.05, perform a hypothesis test to determine if Edalight’s goal has been achieved.
b. Verify your results using PHStat.
c. Interpret the p value obtained from the software.