A-level Mathematics/MEI/S1/The Binomial Distribution
Conditions for a situation to be normally distributed
If a situation is to be binomially distributed it must satisfy the following conditions.
1. The event must have only two possible outcomes.The outcomes are normally termed as 'success' ( denoted by ) and failure ( denoted by )
2. The two outcomes must be independent.
Converting Binomial distribution into a Normal Distribution 
If an event is to be repeated number of times with constant (independent) probabilities of both the possible outcomes occurring, by calculating the mean ( ) of the distribution and the variance ( ) of the distribution, the binomial distribution can be converted into an approximate normal distribution.