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Questions are from The Practice of Statistics for Business and Economics, 3rd Ed

ID: 3124925 • Letter: Q

Question

Questions are from The Practice of Statistics for Business and Economics, 3rd Ed. 4.34 World Internet Usage.

Approximately 23.6% of the world’s population uses the Internet (as of December 2008). Furthermore, a randomly chosen Internet user has the following probabilities of being from the given region of the world: (a) What is the probability of a randomly chosen Internet user not being from one of the four regions explicitly listed in this table. (b) What is the probability of a randomly chosen Internet user living in either Asia or Europe? (c) What is the probability of a randomly chosen Internet user not living in North America?

Region/Probability

Asia / .411

Europe / 0.247

North America / 0.156

Latin America /  0.110

Explanation / Answer

a) The probability of a randomly chosen Internet user not being from one of the four regions explicitly listed in the table is given by,

1 - { 0.411+0.247+0.156+0.110}

= 1 - 0.924

= 0.076

b) The probability of a randomly chosen Internet user living in either Asia or Europe is given by,

p ( A ) + p ( E) = 0.411 + 0.247 = 0.658

c) The probability of a randomly chosen Internet user not living in North America is given by,

1 - p ( North America)

= 1 - 0.156 = 0.844