Discrete Random Variables Flashcards

1
Q

Continuous Random Variable

A

If Fx is continuous and differentiable with derivative fx, then X is a continuous random variable. fx is the probability density function of X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Discrete Random Variable

A

Suppose Ω is a countable sample space. Then a function X: Ω-R is called a discrete random variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Joint Distribution Function

A

F(x1,…,xn)=P(X1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Marginal Distribution Function

A

Distribution function of a single random variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Joint Probability Mass Function

A

p(x1,…,xn)=P(X1=x1,…,Xn=xn) where X1,…,Xn are discrete random variables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

p-value

A

The observed significance level of a test where the probability of obtaining a value of the test statistic is at least as extreme as that observed under H₀

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Power

A

1-β

Measures the test’s ability to detect a departure from H₀ when it exists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Type 1 error

A

When we reject H₀ when it is true. This has probability α

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Type 2 error

A

When we accept H₀ when it is in fact false. This has probability β

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Linear Statistical Model

A

The regression curve is a linear function of the parameters in the model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Regression Curve

A

μ(x) as a function of x

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Binomial distribution

A

X is the number of successes recorded during a sequence of n>1 independent Bernoulli trials, each with the same probability of success

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The geometric distribution

A

X is the number of Bernoulli the trials required before a success is observed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The negative binomial distribution

A

X is the number of independent Bernoulli trials required before r>1 successes have been observed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hypergeometric distribution

A

X is the number of objects having a particular attribute when we draw n objects at random from a population of N, of which M have the attribute of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Poisson distribution

A

X is the number of ‘accidents’ occurring during a time period of fixed duration

17
Q

Exponential distribution

A

Starting at times zero let X be the time until the first accident occurs with the press on process rate of Lambda

18
Q

The gamma distribution

A

The time until the kth accident in a Poisson process

19
Q

Beta distribution

A

A random variable that represents a proportion measured on some continuous scale

20
Q

Central limit theorem

A

If X1X2 are independent random variables having a common distribution with means μ invariance sigma squared then X by has approximately normal distribution with me and me you invariant sigma squared divided by N for a large n

21
Q

Estimation

A

A statistic whose realised value is taking is the estimate of some unknown parameter

22
Q

Null Hypothesis

A

On assumption about a parameter which we wish to test on the basis of available data

23
Q

Alternative Hypothesis

A

Supported when the data does not support H₀

24
Q

Test Statistic

A

A distribution known under H₀ and ‘large’ values of |T| are inconsistent with H₀

25
Q

Assumptions for Hypothesis Test

A

Normality (sample means)
Independence
Sample Variances are scaled chi-square
In large samples they hold - Central Limit Theorem

26
Q

Least Squares Method Assumptions

A

σ² constant

Independent