A manufacturer of electric lamps is testing a new production method that will be considered acceptable if the lamps produced by this method result in a normal population with an average life of 2,400 hours and a standard deviation equal to 300. A sample of 100 lamps produced by this method has an average life of 2,320 hours. Can the hypothesis of validity for the new manufacturing process be accepted with a risk equal to or less than 5%?
I did z= x- μ/ σ / sqrt(n) = 2320 - 400/ 300/sqrt(100) = -80/30 = 2.6666
This gave me a p value of .0038. Multiply it by 2 and get .0076 which is less than .05?
I did z= x- μ/ σ / sqrt(n) = 2320 - 400/ 300/sqrt(100) = -80/30 = 2.6666
This gave me a p value of .0038. Multiply it by 2 and get .0076 which is less than .05?