The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. It can be concluded that approximately 68% of the bulbs will last between:

It can be concluded that approximately 68% of the bulbs will last between:1125 and 1275 hours

Step-by-step explanation:

For this case we know that the random variable X "iife of a particular brand of light bulb " and we know the following distribution:

And we can use the empirical rule for this case and we know that 68% of the values are within one deviation from the mean and we can find the limits like this:

It can be concluded that approximately 68% of the bulbs will last between:1125 and 1275 hours

step-by-step explanation:

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