A manufacturer of 8-watt LED downlights has past data that shows the lifespan of the downlight is normally distributed with mean 50,000 hours and standard deviation 5,000 hours. Let ? be the lifespan...

A manufacturer of 8-watt LED downlights has past data that shows the lifespan of the
downlight is normally distributed with mean 50,000 hours and standard deviation 5,000 hours.
Let ? be the lifespan of a random selected LED 8-watt downlight from this manufacturer.

g. A random sample of twenty-five 8-watt LED downlights produced by this manufacturer is selected. State the type of distribution and the value/s of the parameter/s for the mean of this sample.
h. Calculate the probability that the average lifespan of this sample is less than 47,500 hours.