Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. math exams: January 2012

Sunday, January 29, 2012

Question Statistics 1/29/2012 6:35

The mean length of life of a certain tool is 41.5 hours with a standard deviation of 2.5 hours. What is the probability that a simple random sample of size 50 drawn from this population will have a mean of between 40.5 and 42 hours ?

Answer : $0.9215$