Statistik Flashcards

1
Q

What are characteristics of a binomial distribution ?

A

Describes a number of successes
Constant success probability
Fixed number of independent trials
Two possible outcomes (success/failure)

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2
Q

What would be an example of a binomial distribution ?

A

Flipping a coin 10 times

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3
Q

What is the formula for the standard deviation of a binomial distribution?

A

square root(n*p(1-p))

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4
Q

What are characteristics of a position distribution ?

A

Models probability of a given number of events in a fixed time period or space.
Events can oi our independent of each other

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5
Q

What is a typical example for a Poisson distribution ?

A

Number of customers arriving at a store during a specific time period

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6
Q

How is the standard deviation of a poussin distribution calculated ?

A

square root(mean)

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7
Q

What are characteristics of a normal distribution ?

A

Large sample size
Continuous probability

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8
Q

What is a typical example of a standard normal distribution ?

A

Distribution of weight or IQ

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9
Q

How is the standard deviation of a normal distribution calculated?

A

square root of variance

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10
Q

What is. The central limit theorem ?

A

The distribution of a mean of a large enough sample, with a finite mean and variance will be normally distributed.

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11
Q

What is the null hypothesis ?

A

Statement being tested in the hypothesis test

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12
Q

How is the estimated standard error of the mean/ degree of freedom calculated ?

A

Sample standard variation: square root of sample size

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13
Q

What is the P-value

A

The probability, that indicates the level of evidence against the null hypothesis

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14
Q

What is a one tailed hypothesis ?

A

When a hypothesis specified the direction of an effect
(Higher than, lower than)

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15
Q

What is a two tailed hypothesis ?

A

When the hypothesis is not specific on the direction of effect
(Higher and lower)

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16
Q

How is the 95% confidence interval calculated

A

Sample mean +-(critical value)*(standard error)

17
Q

How is the degree of freedom calculated ?

A

N-1

18
Q

When is a hypothesis true

A

When the p-value is smaller than 0.05