Statistics

Question 1

Nominal Data

Answer 1

Data classified into mutually exclusive categories lacking intrinsic order. I.E. Phone numbers, colors, types of plants, etc.

Question 2

Ordinal Data

Answer 2

Ordered categories that imply ranking. I.E. Letter grades, race times, best voted restaurants, etc.

Question 3

Interval Data

Answer 3

Ordered numerical data where the difference between each point is equal from one another. I.E temperature, time, mark grading (1-100).

Question 4

Ratio Data

Answer 4

Numerical data where there is equal distance between adjacent values and it has a true 0. I.E. Temperature in Kelvin, height, age in years.

Question 5

Variable

Answer 5

A quantity that can be assumed to vary or be capable of varying in value. Such as X=2

Question 6

Quantitative variable

Answer 6

A variable in which the actual numerical value is meaningful. Represents an interval or ratio measurement.

Question 7

Qualitative variable

Answer 7

A variable in which the numerical value is not meaningful. Represents an nominal or ordinal measurement.

Question 8

Population

Answer 8

The total of some group. I.E. People on earth, ducks candles in a candelabra, ducks in a pond, etc.

Question 9

Sample

Answer 9

A subset of a population. I.E. single ducks in a pond, melted candles in a candelabra, etc.

Question 10

Descriptive statistics

Answer 10

Statistics that describe the characteristics of some values in a population or a sample of a population. I.E. A mean, median, or mode.

Question 11

Inferential Statistics

Answer 11

Statistics that use probability to determine population characteristics. Taking a sample and making inferences about a population.

Question 12

Distribution

Answer 12

The overall shape of all observed data. How it looks when put into a histogram, density plot, scatter plot, etc.

Question 13

Range

Answer 13

The difference between the largest and the smallest value in a data set.

Question 14

Normal distribution / Gaussian distribution / Bell Curve

Answer 14

Distribution is symmetrical - An equal number of observations fall above and below the mean.

Question 15

Asymmetrical distribution / skewed distribution

Answer 15

More observations fall to one side or the other of the mean. They skew right or left when the large outliers are above or below the mean.

Question 16

Central Tendency

Answer 16

A single value that attempts to describe a data set by identifying the the central position within that set of data. I.E. Mean, Median, and mode.

Question 17

Mean

Answer 17

The average of a distribution. I.E. (2 + 3 + 4 + 5)/4,

Question 18

Median

Answer 18

The middle value of a ranked distribution. If there are two middle values, it would be the average of the two values.

Question 19

Mode

Answer 19

The most frequent number in a distribution.

Question 20

Inter-quartile range (IQR)

Answer 20

The difference in values between the 75th and 25th percentile in a distribution. the 1/4 and 3/4 cutoff points.

Question 21

Variance (the math kind)

Answer 21

a measure of how data points differ from the mean.

Question 22

Hypothesis test

Answer 22

A way of testing a hypothesis. You’re basically testing whether your results are valid by figuring out the odds that your results have happened by chance. Disprove a null hypothesis.

Question 23

Null hypothesis

Answer 23

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

Question 24

Standard deviation

Answer 24

A measure of the amount of variation in a set of values. low = more values closer to the mean. High = more values further from the mean.

Question 25

Test statistic

Answer 25

Number calculated from a statistical test of a hypothesis. It shows how closely your observed data match the distribution expected under the null hypothesis.

The test statistic is used to calculate the p-value of your results, helping to decide whether to reject your null hypothesis.

Question 26

Confidence interval

Answer 26

The confidence interval is the range of values that you expect your estimate to fall between a certain percentage of the time if you run your experiment again or re-sample the population in the same way.

Question 27

T-test

Answer 27

A t-test is a statistical test that is used to compare the means of two groups. It is often used in hypothesis testing to determine whether a process or treatment actually has an effect on the population of interest, or whether two groups are different from one another.

Question 28

ANOVA analysis

Answer 28

Anlysis of variance test. used to analyze the difference between the means of more than two groups.

Question 29

Chi square test

Answer 29

A chi-square test is a statistical test used to compare observed results with expected results.