7) A package of light bulbs is advertised to last for an average of 750 hours. Assume thatthe lifetime of a light bulb is modeled by an exponential distribution. Further,

assume thataverage represents the mean. Let T denote the random number of hours that the light bulblasts. a) Find the probability that the light bulb burns out before the average life expectancy ofthe bulb. That is, find P{T < 750}. b) Find the time T when there is a fifty percent chance that the bulb has burned out. Thatis find the median, which is the value m such that P{T < m} = 0.50.

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