The Central Intelligence Agency (CIA) has specialists who analyze the frequencies of letters of the alphabet in an attempt to decipher intercepted messages. In standard English text, the letter s is...

The Central Intelligence Agency (CIA) has specialists who analyze the frequencies of letters of the alphabet in an attempt to decipher intercepted messages. In standard English text, the letter s is used at a rate of 5.74%.


Find the mean and standard deviation for the number of times the letter s will be found on atypical page of 2500 characters.

(Round answer to one decimal place.)

μ=μ=

(Round answer to two decimal places.)

σ=σ=


Give the interval of usual values for the number of s's appearing on a page of 2500 characters.

(Enter answer as an interval using square-brackets only with whole numbers.)

usual values =


In an intercepted message sent to a foreign country, a page of 2500 characters is found to have the letter s occurring 188 times. Is this unusual?