Exam 4: Probability

Josh has been given two assignments, assignment A and assignment B.He estimates that the chance of getting a passing grade on assignment A is 60% and the chance of getting a passing grade on assignment B is 50%.If Josh gets a passing grade on assignment A, he figures his chances of getting a passing grade on assignment B increase to 70%.How likely is it that Josh gets a passing grade on assignment A but not on assignment B?

Probability is a number between 0 and 1 that measures the chance or likelihood that some event or set of events will occur.

The following table lists the world's five largest employers, along with their industry and nationality (BBC News, March 19, 2012).You plan to randomly choose one employer from the group.Find the conditional probability that the employer you select is in the defense industry, given that the employer is headquartered in the US.

Josh has been given two assignments, assignment A and assignment B.He estimates that the chance of getting a passing grade on assignment A is 60% and the chance of getting a passing grade on assignment B is 50%.If Josh gets a passing grade on assignment A, he figures his chances of getting a passing grade on assignment B increase to 70%.How likely is it that Josh does NOT get a passing grade on either assignment?

For the cases listed below, in which one would you most likely use the classical approach to assign probability?

According to studies, 62% percent of online teenagers are Facebook users, while 51% are users of Twitter.If 43% are both Facebook and Twitter users, what percent of Twitter users are Facebook users?

In a multi-stage experiment, if there are two outcomes per stage and there are three stages, then the total number of outcomes is six.

The price of Chrysler stock increased on 30% of the trading days.The price of Ford stock increased on 40% of the trading days over the past year.On 60% of the days when the price of Ford stock increased, the price of Ford stock increased as well.On what proportion of the days did neither stock increase in price?

An experiment consists of four outcomes with P(E₁) = 0.2, P(E₂) = 0.3, and P(E₃) = 0.4.The probability of P(E₄) is:

In constructing a probability tree, probabilities beyond the first stage are conditional probabilities and the multiplication rule is used to get end node probabilities.

Which of the following is NOT one of the basic requirements of probability?

Antonia and Bethany played in the same 50 tennis matches last year.Antonia made the finals in 20 of those matches.Bethany made the finals in 15 of the matches.In 12 of the matches, they both made the final.In what proportion of the matches did neither player make it to the final match?

You plan a conference call to present your new marketing proposal to two of your partners in China-Arthur Tang and Barbara Liu.You decide that the probability of Arthur endorsing the proposal is 0.6 and probability of Barbara endorsing the proposal is 0.4.The probability that both will endorse the proposal is put at 0.1.Determine the probability that Barbara will endorse your proposal given that Arthur does not.

If the probability of an economic recovery next year is 0.55, what is the probability that there won't be a recovery?

In a recent survey of local businessmen and businesswomen, 40% of the respondents belong to the Rotary Club, 70% belong to the Chamber of Commerce.30% were members of both.What proportion of the respondents are members of at least one of the groups?

The addition law is potentially helpful when we are interested in computing the probability of:

If the probability that both Microsoft and Intel will have a significant growth in profits next year is 0.4, what is the probability that at least one of them will not?

According to studies, 62% percent of online teenagers are Facebook users, while 51% are users of Twitter.If 43% are both Facebook and Twitter users, what proportion of Facebook users are Twitter users?

In a recent survey of 600 Belkin employees (240 in the US, 210 in Europe, and the remainder in Asia), each employee was asked the question, "Is the company doing enough to support you in your work?" Overall, 64% of the survey participants said yes.The remaining 36% said no.You note that 38% of the participants were US employees who said yes.You also note that 80% of the European employees in the survey said no.What proportion of employees in the survey are employees in Asia who answered no?

The following table lists the world's five largest employers, along with their industry and nationality (BBC News, March 19, 2012).You plan to randomly choose one employer from the group.Find the conditional probability that the employer you select is in the defense industry, given that the employer is headquartered in the US.