Statistik Flashcards
(18 cards)
What are characteristics of a binomial distribution ?
Describes a number of successes
Constant success probability
Fixed number of independent trials
Two possible outcomes (success/failure)
What would be an example of a binomial distribution ?
Flipping a coin 10 times
What is the formula for the standard deviation of a binomial distribution?
square root(n*p(1-p))
What are characteristics of a position distribution ?
Models probability of a given number of events in a fixed time period or space.
Events can oi our independent of each other
What is a typical example for a Poisson distribution ?
Number of customers arriving at a store during a specific time period
How is the standard deviation of a poussin distribution calculated ?
square root(mean)
What are characteristics of a normal distribution ?
Large sample size
Continuous probability
What is a typical example of a standard normal distribution ?
Distribution of weight or IQ
How is the standard deviation of a normal distribution calculated?
square root of variance
What is. The central limit theorem ?
The distribution of a mean of a large enough sample, with a finite mean and variance will be normally distributed.
What is the null hypothesis ?
Statement being tested in the hypothesis test
How is the estimated standard error of the mean/ degree of freedom calculated ?
Sample standard variation: square root of sample size
What is the P-value
The probability, that indicates the level of evidence against the null hypothesis
What is a one tailed hypothesis ?
When a hypothesis specified the direction of an effect
(Higher than, lower than)
What is a two tailed hypothesis ?
When the hypothesis is not specific on the direction of effect
(Higher and lower)
How is the 95% confidence interval calculated
Sample mean +-(critical value)*(standard error)
How is the degree of freedom calculated ?
N-1
When is a hypothesis true
When the p-value is smaller than 0.05
