# What is the probability of A and B?

Asked By: Dailos Martienssen | Last Updated: 14th April, 2020
Category: science space and astronomy
5/5 (158 Views . 33 Votes)
If A and B are independent, then the probability that events A and B both occur is: p(A and B) = p(A) x p(B). In other words, the probability of A and B both occurring is the product of the probability of A and the probability of B. Therefore, the probability of both events is: 1/52 x 1/4 = 1/208 .

Hereof, how do you find the probability of A and B?

Formula for the probability of A and B (independent events): p(A and B) = p(A) * p(B). If the probability of one event doesn't affect the other, you have an independent event. All you do is multiply the probability of one by the probability of another.

Additionally, what is the probability of a given b? If A and B are two events in a sample space S, then the conditional probability of A given B is defined as P(A|B)=P(A∩B)P(B), when P(B)>0.

Subsequently, one may also ask, what is the probability of A or B or both?

The probability that Events A and B both occur is the probability of the intersection of A and B. The probability of the intersection of Events A and B is denoted by P(A ∩ B). If Events A and B are mutually exclusive, P(A ∩ B) = 0.

How do you know if an B is independent?

To test whether two events A and B are independent, calculate P(A), P(B), and P(A ∩ B), and then check whether P(A ∩ B) equals P(A)P(B). If they are equal, A and B are independent; if not, they are dependent.

### Are A and B mutually exclusive?

The definition of being mutually exclusive (disjoint) means that it is impossible for two events to occur together. Given two events, A and B, they are mutually exclusive if (A П B) = 0. If these two events are mutually exclusive, they cannot be independent.

### How do you find the probability of A and B and C?

To calculate the probability of the intersection of more than two events, the conditional probabilities of all of the preceding events must be considered. In the case of three events, A, B, and C, the probability of the intersection P(A and B and C) = P(A)P(B|A)P(C|A and B).

### What is P A or B?

If A is an event and B is another event, then P(A or B) is the probability of either A occurring, orB occurring, or both occurring.

### What is the probability?

Probability = the number of ways of achieving success. the total number of possible outcomes. For example, the probability of flipping a coin and it being heads is ½, because there is 1 way of getting a head and the total number of possible outcomes is 2 (a head or tail). We write P(heads) = ½ .

### What is Bayes rule used for?

Bayes' theorem, named after 18th-century British mathematician Thomas Bayes, is a mathematical formula for determining conditional probability. The theorem provides a way to revise existing predictions or theories (update probabilities) given new or additional evidence.

### What is basic probability?

Basic Concepts of Probability. A probability is a number that reflects the chance or likelihood that a particular event will occur. Probabilities can be expressed as proportions that range from 0 to 1, and they can also be expressed as percentages ranging from 0% to 100%.

### What are the rules of probability?

There are three basic rules associated with probability: the addition, multiplication, and complement rules. The addition rule is used to calculate the probability of event A or event B happening; we express it as: P(A or B) = P(A) + P(B) - P(A and B)

### How do you calculate the expected value?

In statistics and probability analysis, the expected value is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values. By calculating expected values, investors can choose the scenario most likely to give the desired outcome.

### What are the 5 rules of probability?

Basic Probability Rules
• Probability Rule One (For any event A, 0 ≤ P(A) ≤ 1)
• Probability Rule Two (The sum of the probabilities of all possible outcomes is 1)
• Probability Rule Three (The Complement Rule)
• Probabilities Involving Multiple Events.
• Probability Rule Four (Addition Rule for Disjoint Events)
• Finding P(A and B) using Logic.

### Can disjoint events be independent?

Two disjoint events can never be independent, except in the case that one of the events is null. Events are considered disjoint if they never occur at the same time. For example, being a freshman and being a sophomore would be considered disjoint events. Independent events are unrelated events.

### How do you find the probability of none?

To find the probability of at least one of something, calculate the probability of none and then subtract that result from 1. That is, P(at least one) = 1 – P(none). Topford supplies X-Data DVDs in lots of 50, and they have a reported defect rate of 0.5% so the probability of a disk being defective is 0.005.

### Are A and B independent?

Events A and B are independent if the equation P(A∩B) = P(A) · P(B) holds true. You can use the equation to check if events are independent; multiply the probabilities of the two events together to see if they equal the probability of them both happening together.

### What does a given B mean?

P(B|A) means "Event B given Event A" In other words, event A has already happened, now what is the chance of event B? P(B|A) is also called the "Conditional Probability" of B given A.

### What is the multiplication rule?

Multiplication Rule. The rule of multiplication applies to the following situation. Rule of Multiplication If events A and B come from the same sample space, the probability that both A and B occur is equal to the probability the event A occurs times the probability that B occurs, given that A has occurred.

### What is P A B C?

Any probability result that is true for unconditional probability remains true if everything is conditioned on some event. You know that by definition, P(A∣B)=P(A∩B)P(B) and so if we condition everything on C having occurred, we get that P(A∣(BC))=P((A∩B)∣C)P(BC)

### How do you find the Z score?

z = (x – μ) / σ
For example, let's say you have a test score of 190. The test has a mean (μ) of 150 and a standard deviation (σ) of 25. Assuming a normal distribution, your z score would be: z = (x – μ) / σ

### Is the probability of a given b the same as the probability of B given a?

7. Is the probability of “A given B” the same as the probability of “B given A?” Explain. Yes, because due to the General Multiplication Rule, it doesn't matter which set is A and which set is B. You hvae to multiply the probability of A and the probability of B to find the outcome.