Ridge counts on fingerprints are approximately normally distributed, with a mean of about 140 and a standard deviation of 50. It then follows that 68% of the population will have:
A)140 ± 50 ridges
B)140 ± 68 ridges
C)140 ± 100 ridges
D)140 ± 150 ridges

Question

Quizplus · Accepted Answer

The 68% figure refers to the percentage of data within one standard deviation of the mean in a normal distribution, which in this case is 140 ± 50 ridges.

Ridge Counts on Fingerprints Are Approximately Normally Distributed, with a Mean