Problema Solution
Ridge counts on fingerprints are approximately normally distributed, with a mean of about 140 and standard deviation of 50. What does the 68–95–99.7% rule tell us about ridge counts on fingerprints?
68% of people will have 140 ± 50 ridges, 95% will have 140 ± 125, and 99.7% will have 140 ± 150.
68% of people will have 140 ± 150 ridges, 95% will have 140 ± 125, and 99.7% will have 140 ± 50.
68% of people will have 140 ± 150 ridges, 95% will have 140 ± 100, and 99.7% will have 140 ± 50.
68% of people will have 140 ± 50 ridges, 95% will have 140 ± 100 ridges, and 99.7% will have 140 ± 150.
Answer provided by our tutors
In statistics, the 68–95–99.7 rule, also known as the three-sigma rule or empirical rule, states that nearly all values lie within three standard deviations of the mean in a normal distribution.
68.27% of the values lie within one standard deviation of the mean. Similarly, 95.45% of the values lie within two standard deviations of the mean. Nearly all (99.73%) of the values lie within three standard deviations of the mean.
Thus the answer is:
68% of people will have 140 ± 50 ridges, 95% will have 140 ± 100 ridges, and 99.7% will have 140 ± 150.