Answer:
66
Step-by-step explanation:
The Empirical Rule states that 68% of data is between 1 standard deviation in a dataset of normal distribution, 95% falls between 2 standard deviations, and 99.7% between 3.
The mean is 450, and one standard deviation is between 450 ± 50 = 400 and 500. Therefore, we can say that 68% of the data falls between 400 and 500 seconds.
The data includes 97 emergencies, so we just need to find 68% of that, which is 0.68*97 = 65.96 (rounding up to 66)
