Week 4

Question 1

Data

Answer 1

recorded values of qualitative or quantitative observations.

Question 2

Population

Answer 2

the collection of all subjects of interest.

Question 3

Sample

Answer 3

a subset of the population of interest.

Question 4

Parameters

Answer 4

a characteristic of a population.

Question 5

Statistic

Answer 5

a characteristic of a sample.

Question 6

Levels of Measurement

Answer 6

qualitative [nominal (categories that cannot be put in any order) & ordinal (categories that can be ordered)] & quantitative [interval (-infinity to infinity) & ratio (0 to infinity)]

Question 7

Measure of Central Tendency

Answer 7

Mean (average of data points), Median (middle of data points) and Mode (most recurring data point)

Question 8

Measure of Position

Answer 8

Mean, Median, Mode, Min, Max.

Question 9

Measure of Dispersion

Answer 9

Range, frequency, variance, standard deviation.

Question 10

Measures of Relationship

Answer 10

Covariance, Correlation, Regression, Trend, Forecast.

Question 11

Measures of Asymmetry

Answer 11

Skewness and Kurtosis.

Question 12

Statistics

Answer 12

the science of collecting, summarizing, and drawing valid conclusions from data which involves: selecting models to validate hypotheses and test assumptions, determining the relationships between variables, assessing data trends and trajectories, identifying patterns and groupings, detecting mistakes and outliers.

Question 13

Uniform Distribution

Answer 13

distribution (continuous or discrete) whose data points lie within a range and all have equal probability of appearing.

Question 14

Binomial Distribution

Answer 14

discrete probability distribution with parameters n and p of the number of successes in a sequence of n independent experiments and each with its Boolean-valued outcome: success (with probability p) or failure (with probability q = 1-p).

Question 15

Poisson distribution

Answer 15

discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space if these events occur with a known constant mean rate and independently of the time since the last event.

Question 16

Normal distribution

Answer 16

continuous probability distribution whose importance stems from the fact that random variables without known distribution will mimic the distribution if a large enough sample of those random variables are collected (CLT).

Question 17

Central Limit Theorem

Answer 17

no matter the underlying distribution of the dataset, the sampling distributions of the means would approximate a normal distribution. The mean of the sampling distribution would be equal to the mean of the original distribution and the variance would be n times smaller .

Question 18

Hypothesis Testing

Answer 18

the testing of a hypothesis (an idea that can be tested and a supposition or proposed explanation made on the basis of limited evidence as a starting point for further explanation.

Question 19

ANOVA (Analysis of Variance)

Answer 19

a collection of statistical models and their associated estimation procedures used to analyze the difference among means. Based on the law of total variance, ANOVA provides a statistical test of whether two or more population means are equal.

Question 20

Chi-Squared Analysis

Answer 20

a statistical hypothesis test that is valid to perform when the test statistic is chi-squared distributed under the null hypothesis. Used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table.

Question 21

Standardization

Answer 21

the normalization of the normal distribution (N(0,1)) .

Question 22

Z score

Answer 22

the standard score calculated by subtracting the population mean from an individual raw score and dividing the difference by the population standard deviation.

Question 23

Arithmetic mean, Median, Mode

Answer 23

average of data points, center of data points and data point that appears most frequently.

Question 24

Range, Average Deviation, Variance

Answer 24

difference between the maximum and minimum data point, number that indicates how data points deviate from the mean, taking the standard deviation and squaring it.

Question 25

Standard deviation

Answer 25

number that indicates how much data points deviate from the mean.

Question 26

Covariance

Answer 26

a measure of the joint variability of two variables

Question 27

Correlation

Answer 27

a measure of the joint variability of two variables. Standardized measure of covariance.

Question 28

Skewness

Answer 28

a measure of a symmetry that indicates whether the observations in a dataset are concentrated on one side.

Question 29

Probability Sampling

Answer 29

each element from the population dataset has a chance of being deleted as a sample. Ex. Simple, Stratified, Cluster, and Systematic random sampling.

Question 30

Non Probability Sampling

Answer 30

the practice of sampling without the assurance that elements have the equal amount of chance of being selected. Ex. Convenience, Voluntary and Snowball sampling, Quota, and Purposive.

Question 31

Bias

Answer 31

the risk that a subset of a population will not accurately represent the overall population.