Conditional probability

Conditional probability table

In statistics, the conditional probability table (CPT) is defined for a set of discrete and mutually dependent random variables to display conditional probabilities of a single variable with respect to the others (i.e., the probability of each possible value of one variable if we know the values taken on by the other variables). For example, assume there are three random variables where each has states. Then, the conditional probability table of provides the conditional probability values – where the vertical bar means “given the values of” – for each of the K possible values of the variable and for each possible combination of values of This table has cells. In general, for variables with states for each variable the CPT for any one of them has the number of cells equal to the product A conditional probability table can be put into matrix form. As an example with only two variables, the values of with k and j ranging over K values, create a K×K matrix. This matrix is a stochastic matrix since the columns sum to 1; i.e. for all j. For example, suppose that two binary variables x and y have the joint probability distribution given in this table: Each of the four central cells shows the probability of a particular combination of x and y values. The first column sum is the probability that x =0 and y equals any of the values it can have – that is, the column sum 6/9 is the marginal probability that x=0. If we want to find the probability that y=0 given that x=0, we compute the fraction of the probabilities in the x=0 column that have the value y=0, which is 4/9 ÷ 6/9 = 4/6. Likewise, in the same column we find that the probability that y=1 given that x=0 is 2/9 ÷ 6/9 = 2/6. In the same way, we can also find the conditional probabilities for y equalling 0 or 1 given that x=1. Combining these pieces of information gives us this table of conditional probabilities for y: With more than one conditioning variable, the table would still have one row for each potential value of the variable whose conditional probabilities are to be given, and there would be one column for each possible combination of values of the conditioning variables. Moreover, the number of columns in the table could be substantially expanded to display the probabilities of the variable of interest conditional on specific values of only some, rather than all, of the other variables. (Wikipedia).

Video thumbnail

Ex: Determine Conditional Probability from a Table

This video provides two examples of how to determine conditional probability using information given in a table.

From playlist Probability

Video thumbnail

How to find the conditional probability from a tree diagram

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Finding the conditional probability from a tree diagram

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

How to find the conditional probability from a contingency table

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Using a tree diagram to find the conditional probability

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Learn to find the or probability from a tree diagram

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Finding the conditional probability from a two way frequency table

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Using a contingency table to find the conditional probability

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Determining the conditional probability from a contingency table

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Excel Statistical Analysis 19: Conditional Probability 5 Examples

Download Excel File: https://excelisfun.net/files/Ch04-ESA.xlsm pdf notes: https://excelisfun.net/files/Ch04-ESA.pdf Learn about: Topics: 1. (00:00) Introduction 2. (00:40) Define Conditional Probability 3. (02:58) Calculate Conditional Probability From a Cross Tabulated Frequency Table us

From playlist Excel Statistical Analysis for Business Class Playlist of Videos from excelisfun

Video thumbnail

Excel 2010 Statistics 43: Further Explanation of Bayes' Theorem & Posterior Probabilities

Download Excel File #1: https://people.highline.edu/mgirvin/AllClasses/210Excel2010/Content/Ch04/Busn210ch04.xlsm Download Excel File #2: https://people.highline.edu/mgirvin/AllClasses/210Excel2010/Content/Ch04/Busn210ch04SecondFile.xlsm Download pdf file: https://people.highline.edu/mgirv

From playlist Excel 2010 Statistics Formulas Functions Charts PivotTables

Video thumbnail

Excel 2013 Statistical Analysis #30: Bayes’ Theorem to Calculate Posterior Probabilities

Download Excel file: https://people.highline.edu/mgirvin/AllClasses/210Excel2013/Ch04/Excel2013StatisticsChapter04.xlsm Download pdf notes file: https://people.highline.edu/mgirvin/AllClasses/210Excel2013/Ch04/Ch04PDFBusn210.pdf Topics in this video: 1. (00:11) Define and give example of B

From playlist Excel for Statistical Analysis in Business & Economics Free Course at YouTube (75 Videos)

Video thumbnail

Excel 2010 Statistics #41: Joint Probability Table with PivotTable

Download Excel File #1: https://people.highline.edu/mgirvin/AllClasses/210Excel2010/Content/Ch04/Busn210ch04.xlsm Download Excel File #2: https://people.highline.edu/mgirvin/AllClasses/210Excel2010/Content/Ch04/Busn210ch04SecondFile.xlsm Download pdf file: https://people.highline.edu/mgirv

From playlist Excel 2010 Videos

Video thumbnail

Excel Statistics 55: Probability Pivot Table

Download Excel File 1: https://people.highline.edu/mgirvin/AllClasses/210M/Content/ch04/Busn210ch04.xls Download pdf notes: https://people.highline.edu/mgirvin/AllClasses/210M/Content/ch04/StatsBusn210Ch04001.pdf See how to calculate these probabilities with a Pivot Table (PivotTable): 1

From playlist Excel Statistics Business 04: Intro. To Probability

Video thumbnail

Excel 2013 Statistical Analysis #28: Multiplication Law of Probability AND Events (16 Examples)

Download Excel file: https://people.highline.edu/mgirvin/AllClasses/210Excel2013/Ch04/Excel2013StatisticsChapter04.xlsm Download pdf notes file: https://people.highline.edu/mgirvin/AllClasses/210Excel2013/Ch04/Ch04PDFBusn210.pdf Topics in this video: 1. (00:25) Conditional Probability (3 E

From playlist Excel for Statistical Analysis in Business & Economics Free Course at YouTube (75 Videos)

Video thumbnail

Conditional Probability With Tables | Chance of an Orange M&M???

►FULL DISCRETE MATH PLAYLIST: https://www.youtube.com/playlist?list=PLHXZ9OQGMqxersk8fUxiUMSIx0DBqsKZS OTHER COURSE PLAYLISTS: ►CALCULUS I: https://www.youtube.com/playlist?list=PLHXZ9OQGMqxfT9RMcReZ4WcoVILP4k6-m ► CALCULUS II: https://www.youtube.com/playlist?list=PLHXZ9OQGMqxc4ySKTIW19T

From playlist Discrete Math (Full Course: Sets, Logic, Proofs, Probability, Graph Theory, etc)

Video thumbnail

Year 13/A2 Statistics Chapter 2.2 (Conditional Probability)

In this lesson we nail down what is actually meant by "conditional probability" and explore it using a few worked examples. In particular, we're going to see how two-way tables can be used, as well as Venn diagrams, to represent probabilities in a clear and useful way. This lesson is mean

From playlist Year 13/A2 Statistics

Video thumbnail

Excel Statistical Analysis 22: Bayes’ Theorem, Tabular Method, Probability Tree, SUMPRODUCT function

Download Excel File: https://excelisfun.net/files/Ch04-ESA.xlsm pdf notes: https://excelisfun.net/files/Ch04-ESA.pdf Learn about 6 different methods for calculating probabilities using Bayes Theorem. Topics: 1. (00:00) Introduction 2. (00:16) Introduction to Baye’s Theorem with a CPA Test

From playlist Excel Statistical Analysis for Business Class Playlist of Videos from excelisfun

Video thumbnail

How to create a tree diagram from a word problem

👉 Learn how to find the conditional probability of an event. Probability is the chance of an event occurring or not occurring. The probability of an event is given by the number of outcomes divided by the total possible outcomes. Conditional probability is the chance of an event occurring

From playlist Probability

Video thumbnail

Bayesian Networks 3 - Maximum Likelihood | Stanford CS221: AI (Autumn 2019)

For more information about Stanford’s Artificial Intelligence professional and graduate programs, visit: https://stanford.io/2Zlc5Iu Topics: Bayesian Networks Percy Liang, Associate Professor & Dorsa Sadigh, Assistant Professor - Stanford University http://onlinehub.stanford.edu/ Associa

From playlist Stanford CS221: Artificial Intelligence: Principles and Techniques | Autumn 2019

Related pages

Stochastic matrix | Random variable | Binary variable | Joint probability distribution | Conditional probability | Statistics | Matrix (mathematics)