binominal distribution Flashcards
what is binomial distribution?
- distributions that counts the number of successes in a series of independent trials
what is probability used for?
- used to quantify how likely a set of data was obtained by pure chance
what does probability represent?
- varying degrees of uncertainty
- how certain we are about the truth of some situation or the cause of outcome
what is n?
- number of trials
what is p?
- probability of success
state the 4 properties of binomial distribution
- a fixed n, the p remains constant, the trial has two possible outcomes (success and failure), trials must be independent
what is the simplest possible data science?
- statistics of coin tossing
what is the probability of getting heads/ tails assumed to be?
- 0.5
- 50%
what do you do to intuitive statistics?
- quantify the statistics using binominal distribution
- calculate the probability of getting k heads in n tosses where the probability of getting heads for each toss is q
what is the equation for probability?
Bi (k/n, q)
what does probability ( A/B ) refer to?
- probability of obtaining A on the condition of B
what is probability (A/B) considered as?
- considered as a function that returns a value between 0 and 1 for given parameters k, n and q
what can you do with the equation of probability?
- can mathematically derive an equal calculating Bi (k/n, q)
- but there is an intuitive way to understand how such function looks like
what can you count?
- how many possible combinations of coins you get k heads out of n tosses
what can you describe the results of tossing a coin 10 time as? what can you find?
- sequence of heads (H) and tails (T)
- among all possible cases, you will sometimes get a sequence that has k= 3 heads
how do you work out probability of coin tosses?
Bi (k/ n, q) = number of sequences with k- heads/ number of all possible sequences
why would you not count number of sequences?
- too tedious and time consuming
what does a decision tree visualise?
- multiple coin toss can be visualised as a connection of branches