The phrase "adding the probability of" is correct and usable in written English.
It can be used in contexts involving statistics, mathematics, or probability theory when discussing the combination of different probabilities.
Example: "In order to find the overall likelihood of success, we will be adding the probability of each individual event occurring."
Alternatives: "calculating the likelihood of" or "summing the probabilities of".
Consequently, it makes no sense to try to compute the probability of an event by "adding" the probabilities of the individual outcomes making up the event, because each individual outcome has probability 0. A closely related experiment, although at first there appears to be no connection, arises as follows.
But farther inland, he added, the probability of severe flooding is high if the storm stalls for several days once it makes landfall, as predicted.
Surprisingly, when a simple island model of population structure (Wright 1930) is added, the probability of fixation does not change even though the population structure leads to an increase in the effective population size.
As more vTopo molecules are added, the probability of finding the cleavage site increases linearly because more enzyme molecules (n) are scanning each substrate molecule for the single recognition site [E n ·MCsp].
The Cancer registry recorded deaths from all causes for a cohort of people (smokers, quitters and never-smokers) who had been diagnosed with lung cancer, so, as for the stroke death probabilities, it was not necessary to add the probability of dying from other causes, and the same death probabilities were used for both smokers and quitters.
We found only two independent predictors of good QOL at six months after AKI: a higher EQ-5D index at ICU admission was associated with a higher probability of a good QOL and lack of hypertension as a chronic condition added the probability of a good QOL.
As these studies recorded deaths from all causes for a cohort of people (smokers, quitters and never-smokers) who had experienced a stroke, it was not necessary to add the probability of dying from other causes, and the same death probabilities were used for both smokers and quitters.
We then have a better estimation for the total probability amplitude by adding the probability amplitudes of these two possibilities to our original simple estimate.
And when asked to assess the probability of a conditional, people should give a response in which they should add the probabilities of the three cases that are represented in the conditional interpretation, as I showed before.
