The following formula is involved in the calculation of conditional probability values:

Conditional probability:
where P(A and B) is the joint probability of events A and B, and P(B) is the probability of event B.

The following references can be used to cite this conditional probability calculator:
 Soper, D.S. (2015). Conditional Probability Calculator [Software]. Available from http://www.danielsoper.com/statcalc 
 Keller, G. (2011). Statistics for Management and Economics (9th edition). Mason, OH: SouthWestern Cengage. 