Statistics – Normal Distribution

A light bulb manufacturer claims her bulbs have a population meanlife of 1,000 hours. Is this claim justified at the .05 level if a random sampleof 25 bulbs has a sample mean of 994 hours with a standard deviationof 30 hours? Assume the population life expectancy of the bulbs is normally distributed.

H0: m = 1000 vs Ha: m <> 1000

Critical two-tailed z- acores at a = 0.05 are -1.96 and …

The expert examines if light bulb manufacturer claims in statistics are normal distributed. A complete, neat and step-by-step solution is provided.