Question

In: Statistics and Probability

The English alphabet has 26 letters. There are 6 vowels. (a, e, i, o, u, and...

The English alphabet has 26 letters. There are 6 vowels. (a, e, i, o, u, and sometimes y). Suppose we randomly select 8 letters from the alphabet without replacement. Let X = the number of vowels chosen (including y as a vowel).

a. How many possible ways are there to select the 8 out of 26 letters (order does not matter) without replacement?
b. What is the probability that X = 2
c. What is the probability that X=1?
d. What is the probability that X < 3?
e. What is the expected value of X?
f. What is the standard deviation of X?
g. What is the probability that X is within 1.1 standard deviations of its expected value?
h Execute the R command "sample(letters,8)". How many vowels did you get?

Solutions

Expert Solution

Answer h. We get 2 vowels


Related Solutions

4. The Hawaiian alphabet has twelve letters: five vowels (a, e, i, o, and u) and...
4. The Hawaiian alphabet has twelve letters: five vowels (a, e, i, o, and u) and seven consonants (h, k, l, m, n, p, and w). For the purpose of this exercise we will define an n–letter “word” as an ordered collection of n of these twelve letters with repeats allowed. Obviously, most such “words” will be nonsense words. a) How many possible four–letter Hawaiian “words” are there? b) What is the probability a randomly selected four–letter “word” has no...
How many ways are there to order the 26 letters of the alphabet so that no two of the vowels a, e, i, o,u appear consecutively and the last letter in the ordering is not a vowel?
  (a) How many ways are there to order the 26 letters of the alphabet so that no two of the vowels a, e, i, o,u appear consecutively and the last letter in the ordering is not a vowel? Hint: Every vowel appears to the left of a consonant. (b) How many ways are there to order the 26 letters of the alphabet so that there are at least two consonants immediately following each vowel? (c) In how many different...
Question 13 We define the letters 'a', 'e', 'i', 'o' and 'u' as vowels. We do...
Question 13 We define the letters 'a', 'e', 'i', 'o' and 'u' as vowels. We do not consider any other letter as a vowel. Write a function named initialVowels() that returns a list of words in a body of text that begin with a vowel. Include both capitalized and lower case instances of the vowels. A word should appear in the return list at most once, no matter how many times is occurs in the input string. Input: a string...
In the game of ScrabbleTM, the letters of the English alphabet are inscribed on tiles
In the game of ScrabbleTM, the letters of the English alphabet are inscribed on tiles and a prescribed number of tiles are provided for each letter. Consider an ensemble of ScrabbleTM tiles with a probability distribution defined by the frequency of tiles in the box. Explain how to calculate the information entropy of this ensemble. It is not necessary to actually Compute the entropy, but you can if you wish.    
6. Passwords are composed from lower- and uppercase letters of the English alphabet,digits and 34 special...
6. Passwords are composed from lower- and uppercase letters of the English alphabet,digits and 34 special characters. What is the exponential generating function of the sequence an=number of passwords with at least one capital letter, one number and one special character.
Each of the first 6 letters of the alphabet is printed on a separate card. The...
Each of the first 6 letters of the alphabet is printed on a separate card. The letter “a” is printed twice. What is the probability of drawing 4 cards and getting the letters f, a, d, a in that order? Same question if the order does not matter.
Using the English alphabet (i.e., mod 26 arithmetic) let plaintext = {p1, p2,… , pn} and...
Using the English alphabet (i.e., mod 26 arithmetic) let plaintext = {p1, p2,… , pn} and corresponding ciphertext = {c1, c2,… , cn}. Suppose the encryption function is  ci = pi + 12 (mod 26), what should be the decryption function. If you receive the ciphertext message YMDWNQXX, decrypt to recover the plaintext. What is the decryption function, and the recovered plaintext?  
9. The Central Intelligence Agency has specialists who analyze the frequencies of letters of the alphabet...
9. The Central Intelligence Agency has specialists who analyze the frequencies of letters of the alphabet in an attempt to decipher intercepted messages that are sent as ciphered text. In standard English text, the letter r is used at a rate of 6%. a. Find the mean and standard deviation for the number of times the letter r will be found on a typical page of 2600 characters. (1 dp) b. In an intercepted ciphered message sent to Iran, a...
Solve the partial differential equation by Laplace transformu_x (x,t)+u_t (x,t)=e^3t given that u(x,o)=0 , u(o,t)=e^3t
Solve the partial differential equation by Laplace transformu_x (x,t)+u_t (x,t)=e^3t given that u(x,o)=0 , u(o,t)=e^3t
For a game that takes user input of certain letters, Upper: O,C,I,Z; Lower: o,c,i,z. The board...
For a game that takes user input of certain letters, Upper: O,C,I,Z; Lower: o,c,i,z. The board is a 4 by 4 matrix and the numbers on the right are the positon that correspond with the dots. So if player 2 statisfies the requirement for the winning condition. Winning conditions being 4 letters in a row of (all upper case-- Z I C O ), (all straight-line-- Z I i I), (all consonants - Z z C c), (all curved-- C...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT