Now, use the table of the standardised normal distribution .
The life-time of a popular computer flatscreen is known to follow a normal distribution with a mean μ = 2000 hours and standard deviation σ = 200 hours. If a computer flatscreen is selected at random, find the probability that it will last for:
Less than 2500 hours.
More than 1900 hours.
Between 2000 and 2400 hours.
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