frequency distributions

Question 1

What is frequency distribution?

Answer 1

It is a variable that represents the observations with regards to the frequencies of values within the entire range of the values.

Question 2

What are the 3 properties of a distribution?

Answer 2

Central tendency, spread or dispersion, and shape of distribution

Question 3

What is central tendency?

Answer 3

The constant.

Question 4

What is spread or dispersion?

Answer 4

The consistent spread

Question 5

What is the shape of distribution?

Answer 5

The symmetric, skewed, positive, negative, uniform, symmetric etc. uniform is the same height, skewed positive and negative, symmetric is normal like a pyramid.

Question 6

What are the 2 types of departures which affects normality?

Answer 6

Skewness- asymmetry and kurtosis, the measure of flatness.

Question 7

What is normal distribution?

Answer 7

When the graph has the right bell shape to it, it is normal distribution. This area has to add to 100%.

Question 8

What is standard normal distribution?

Answer 8

Mean of 0, and a standard deviation of 1.

Question 9

What are confidence intervals?

Answer 9

The sample means are normally distributed around the population mean with a standard error of the equation. Ox = O over root of n

Question 10

What are the discrete distribution?

Answer 10

Binomial (Bernoulli, uniform, hypergeometric), poisson (negative, binomial, zero-inflated)

Question 11

when do you used discrete distribution?

Answer 11

This type of distribution is when: you have applied binary data, each of the n trials have 2 possible outcomes, each trial has the same probability of success, and the probability failure is 1.

Question 12

what is Bernoulli distribution ?

Answer 12

Bernoulli distribution is a special case of binomial distribution, where there is a single experiment. Eg. Flip of a coin

Question 13

what is uniform distribution?

Answer 13

Uniform: when there are multiple outcomes with equal probability

Question 14

what us hypergeometric distribution?

Answer 14

Hypergeometric: binomial distribution without replacement. Where individuals are removed from the population and not replaced.

Question 15

what is poisson distribution?

Answer 15

Poisson: describes the number of events occurring in a given time period or space. Occurrences are random and independent. Can be used to explore the form of distribution and test for randomness.

Question 16

what is negative binomial distribution?

Answer 16

Negative binomial: variation of the poisson distribution. Used to describe clumped populations where there is an inherent approbation. Zero-inflated poisson- anther variation of poisson distribution, used when there is an excess of zero counts in the data.

Question 17

What are continuous distributions?

Answer 17

Uniform chi-squared, student t test, exponential, bimodal, and multimodal.

Question 18

what is chi squared distribution?

Answer 18

What is the chi-squared? Distribution of the sum of squares or normally distributed values. Asymmetric, varies from 0 to infinity.

Question 19

what is student t test distribution?

Answer 19

Student t test: flatter and longer. Basis of student t test- distribution of the derivations from the mean divided by the sample standard error.

Question 20

what is exponential distribution?

Answer 20

Exponential: represents constant probability of increase

Question 21

what is bimodal distribution?

Answer 21

Bimodal: distribution with 2 modes. Useful for population where there is distinct separation.

Question 22

what is multimodal distribution?

Answer 22

Multimodal: distribution with multiple modes.