Chapter 6 - Statistical distributions Flashcards
What is a random variable?
A variable whose value depends on the outcomes of a random event
What is the sample space?
The range of values that a random variable can take
What is a discrete variable?
One which can only take certain numerical values
What is a random variable?
One where the outcome isn’t known until the experiment is carried out
What will the sum of all the probabilities for an event add up to?
1
What does a probability mass function look like?
P(X=x)
What is a uniform distribution?
All probabilities are the same
When can you model X with a binomial distribution? (4)
When there are a fixed number of trials
When there are two possible outcomes
When there is a fixed probability of success
When the trials are independent of each other
What does the binomial distribution look like?
X ~ B (n,p)
What does n represent in the binomial distribution?
The number of trials
What does p represent in the binomial distribution?
The probability of success
What is another way to represent binomial distribution?
P(X=r) = (n) p^r (1-p)^n-r
(p)
What calculation should you use to find when x>y?
1-P(x≤y)
What calculation should you use to find when x≤y?
P(x≤y)
What calculation should you use to find when x≥y?
1-P(x≤(y-1))
