The technology consultancy Data-Genetics published the online document PIN analysis. In addition to analyzing PIN numbers, passwords trends were examined. Seven million all-numeric passwords were collected and yielded the following estimate of the probability distribution of the number of digits used in an all-numeric password.

On average, approximately how many digits would you expect an allnumeric password to have? Explain your answer.

Digits Probability Digits Probability 0.492 0.092 0.178 0.073 0.113 0.029 0.015 0.004 0.003 0.001 10 12 13