Exam 6: Probability

Construction Bids ​ A construction company has submitted bids on two separate state contracts,A and B.The company feels that it has a 60% chance of winning contract A,and a 50% chance of winning contract B.Furthermore,the company believes that it has an 80% chance of winning contract A if it wins contract B. ​ ​ -{Construction Bids Narrative} What is the probability that the company will win neither contract?

Tea and Seltzer Suppose 55 percent of adults drink tea,45 percent drink seltzer,and 10 percent drink both. ​ ​ -{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult doesn't drink tea or seltzer?

Marital Status An insurance company has collected the following data on the gender and marital status of 570 customers. Suppose that a customer is selected at random. ​ ​ -{Marital Status Narrative} Develop the joint probability table.

If two events are mutually exclusive,what is the probability that one or the other occurs?

Tea and Seltzer Suppose 55 percent of adults drink tea,45 percent drink seltzer,and 10 percent drink both. ​ ​ -{Tea and Seltzer Narrative} What is the probability that a randomly chosen adult does not drink seltzer?

The sample space of the toss of a balanced die is S = {1,2,3,4,5,6}.If the die is balanced,each simple event (outcome)has the same probability.Find the probability of the following events: a.Rolling an odd number b.Rolling a number less than or equal to 3 c.Rolling a number greater than or equal to 5 d.Rolling a number between 2 and 5,inclusive.

The relative frequency approach to probability uses long term relative frequencies,often based on past data.

Of the last 500 customers entering a supermarket,50 have purchased a wireless phone.If the relative frequency approach for assigning probabilities is used,the probability that the next customer will purchase a wireless phone is

P(A|B)is the conditional probability of ____________________ given ____________________.

Business Majors Suppose 30% of business majors major in accounting.You take a random sample of 3 business majors. ​ ​ -{Business Majors Narrative} What is the chance that at least one majors in accounting?

Construction Bids ​ A construction company has submitted bids on two separate state contracts,A and B.The company feels that it has a 60% chance of winning contract A,and a 50% chance of winning contract B.Furthermore,the company believes that it has an 80% chance of winning contract A if it wins contract B. ​ ​ -{Construction Bids Narrative} If the company wins contract B,what is the probability that it will not win contract A?

Prior probability of an event is the probability of the event before any information affecting it is given.

Which of the following is a requirement of the probabilities assigned to outcome O_i?

Suppose we have two events A and B.We can apply the addition rule to compute the probability that at least one of these events occurs.

If P(B)= .7 and P(A|B)= .7,then P(A and B)= 0.

In problems where the joint probabilities are given,we can compute marginal probabilities by adding across rows and down columns.

The union of events A and B is the event that occurs when either A or B occurs but not both.

Cysts ​ After researching cysts of a particular type,a doctor learns that out of 10,000 such cysts examined,1,500 are malignant and 8,500 are benign.A diagnostic test is available which is accurate 80% of the time (whether the cyst is malignant or not).The doctor has discovered the same type of cyst in a patient. ​ ​ -{Cysts Narrative} What is the probability that the patient will test negative?

If P(A)= 0.4 and P(B)= 0.6,then A and B must be mutually exclusive.

The ____________________ rule is used to calculate the joint probability of two events.