How do you find the probability of A and B dependent?

Asked By: Luetta Stolz | Last Updated: 22nd April, 2020
Category: science physics
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If they are dependent, then P(A and B) = P(A)*P(B|A) which is the probability of A times the probability of "B happening if A has occurred," which is different than the "Probability of B if A has not occurred."

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Regarding this, how do you find the probability of A and B if they are dependent?

The probability of A and B means that we want to know the probability of two events happening at the same time. There's a couple of different formulas, depending on if you have dependent events or independent events. Formula for the probability of A and B (independent events): p(A and B) = p(A) * p(B).

Also Know, how do you find b given a? This probability is written P(B|A), notation for the probability of B given A. In the case where events A and B are independent (where event A has no effect on the probability of event B), the conditional probability of event B given event A is simply the probability of event B, that is P(B). P(A and B) = P(A)P(B|A).

Likewise, people ask, 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.

How do you calculate the probability?

Divide the number of events by the number of possible outcomes. This will give us the probability of a single event occurring. In the case of rolling a 3 on a die, the number of events is 1 (there's only a single 3 on each die), and the number of outcomes is 6.

38 Related Question Answers Found

What is the formula for independent events?

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 is the difference between dependent and independent probability?

Dependent events influence the probability of other events – or their probability of occurring is affected by other events. Independent events do not affect one another and do not increase or decrease the probability of another event happening.

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 dependent events?

= P(A)^P(B) which is just the probability of A times the probability of B. If they are dependent, then P(A and B) = P(A)*P(B|A) which is the probability of A times the probability of "B happening if A has occurred," which is different than the "Probability of B if A has not occurred."

What are examples of dependent events?


Events are dependent if the outcome of one event affects the outcome of another. For example, if you draw two colored balls from a bag and the first ball is not replaced before you draw the second ball then the outcome of the second draw will be affected by the outcome of the first draw.

What are dependent events?

Definition: Two events are dependent if the outcome or occurrence of the first affects the outcome or occurrence of the second so that the probability is changed.

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 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.

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.

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.

How do you find the probability of an event?

The probability of an event is the number of favorable outcomes divided by the total number of outcomes possible. Converting the fraction 35 to a decimal, we would say there is a 0.6 probability of choosing a banana. This basic definition of probability assumes that all the outcomes are equally likely to occur.

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 does P a B mean in statistics?

Definitions and Notation
Two events are mutually exclusive or disjoint if they cannot occur at the same time. The probability that Event A occurs, given that Event B has occurred, is called a conditional probability. The conditional probability of Event A, given Event B, is denoted by the symbol P(A|B).

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.

How do you get the variance?

To calculate variance, start by calculating the mean, or average, of your sample. Then, subtract the mean from each data point, and square the differences. Next, add up all of the squared differences. Finally, divide the sum by n minus 1, where n equals the total number of data points in your sample.

How do you know if two events are 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.