Answer:
Step-by-step explanation:
The Empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below
68% of data falls within the first standard deviation from the mean.
95% fall within two standard deviations.
99.7% fall within three standard deviations.
From the information given, the mean is 39 and the standard deviation is 3.
99.7% of the number of potholes in any given 1 mile stretch of freeway pavement in Pennsylvania would fall within one standard deviation.
standard deviations = 3
39 - 3 = 36
39 + 3 = 42
Therefore, the approximate proportion of 1-mile long roadways with potholes numbering between 36 and 45 is 0.997
