Chapter 6 discusses discrete probability distributions and includes an analysis by the CIA of letter frequencies in English text for deciphering messages. The letter 'e' is noted to occur most frequently in standard English at 12.702%. An intercepted message to Iraq with 1516 characters shows 'e' occurring 175 times, raising the question of whether this frequency is unusual.

1. Statistics - Chapter 6 Discrete Probability Distributions
The Central Intelligence Agency has specialists who analyze the frequencies of letters of the
alphabet in an attempt to decipher intercepted messages. In standard English text, the letter e is
used most often at a rate of 12.702% . In an intercepted message sent to Iraq, a page of 1516
characters is found to have the letter e occurring 175 times. Is this unusual?