Answer:
99.7% of the distribution will be between 600 hours and 900 hours.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 750
Standard deviation = 50
What percent of the distribution will be between 600 hours and 900 hours?
600 = 750 - 3*50
600 is 3 standard deviations below the mean
900 = 750 + 3*50
900 is 3 standard deviations above the mean
By the Empirical Rule, 99.7% of the distribution will be between 600 hours and 900 hours.
