The amount of time a certain brand of light bulb lasts is normally distributed with a
mean of 1600 hours and a standard deviation of 70 hours. Using the empirical rule,
determine what interval of hours represents the lifespan of the middle 99.7% of light
bulbs.
help fast please!!

Respuesta :

Using the Empirical Rule, it is found that the interval of hours that represents the lifespan of the middle 99.7% of light bulbs is (1390, 1810).

What does the Empirical Rule state?

It states that, for a normally distributed random variable:

  • Approximately 68% of the measures are within 1 standard deviation of the mean.
  • Approximately 95% of the measures are within 2 standard deviations of  the mean.
  • Approximately 99.7% of the measures are within 3 standard deviations of the mean.

The middle 99.7% is within 3 standard deviations of the mean, hence:

  • 1600 - 3 x 70 = 1390.
  • 1600 + 3 x 70 = 1810.

More can be learned about the Empirical Rule at https://brainly.com/question/24537145

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