Exam 4: Introduction to Probability

Two stocks, A and B, have a historical correlation indistinguishable from zero. The probability that stock A increases next year is 0.2, and the probability that stock B increases next year is 0.4. Calculate the probability that A and B both increase next year.

Find the missing values marked xx and yy in the following contingency table.

Events are collectively exhaustive if ________.

Mark Zuckerberg, the founder of Facebook, announced that he will eat meat only from animals that he has killed himself (Vanity Fair, November 2011). Suppose 257 people were asked, "Does the idea of killing your own food appeal to you, or not?" The accompanying contingency table, cross-classified by gender, is produced from the 187 respondents. Given that the respondent is male, the probability that he feels that the idea of killing his own food is appealing is the closest to ________.

Let P(A) = 0.4, P(B|A) = 0.5, and P(B|A^c) = 0.25. Compute P(B).

A recent survey shows that the probability of a college student drinking alcohol is 0.6. Further, given that the student is over 21 years old, the probability of drinking alcohol is 0.8. It is also known that 30% of the college students are over 21 years old. The probability of drinking or being over 21 years old is ________.

Consider these events. A = The survey respondent is less than 40 years old. B = The survey respondent is 40 years or older. Events A and B are mutually exclusive and exhaustive.

Two events A and B can be both mutually exclusive and independent at the same time.

Permutations are used when the order in which different objects are arranged matters.

Two hundred people were asked if they had read a book in the last month. The accompanying contingency table, cross-classified by age, is produced. The probability that a respondent read a book in the last month and is at least 30 years old is the closest to ________.

Mutually exclusive events may share common outcomes of a sample space.

The likelihood of rain has been reported at 80% for next week. Find the odds for rain occurring.

Events are considered ________ if the occurrence of one is related to the probability of the occurrence of the other.

A survey of adults who typically work full time from home recorded their current education level. The results are shown in the table below. The probability that a randomly selected adult who works full time from home has a bachelor's degree or higher is ________.

A(n) ________ probability is calculated as the relative frequency with which an event occurs.

The following contingency table shows the number of customers who bought various brands of digital cameras at Amazon.com and Ritz Camera. Given that the camera was purchased at Ritz Camera, the probability that it was a Sony brand is ________.

Mutually exclusive and collectively exhaustive events contain all outcomes of a sample space, and they do not share any common outcomes.

Mutually exclusive and collectively exhaustive events ________.

The contingency table below provides frequencies for the preferred type of exercise for people under the age of 35 and those 35 years of age or older. Find the probability that an individual prefers running and is under 35 years of age.

What is probability?