Statistic Vocab Unit 1 - 4

Intro to stats

mean

Adding all data then diving by the sum of n 

median

middle is found when the data is arranged in order then looking at the middle

mode

The number(s) that are repeating/appearing most often

range

High - low

Descriptive Stats

• organizing & summarizing information

• include construction of graphs, charts, and tables

• Includes calculations of various descriptive measures

• - Ex: averages, measures of variation, and percentiles

Inferential stats

Methods for drawing and measuring the reliability of conclusion about a population based on information obtained from a sample of the population. 

(words- infer, estimates(s), predicts(ion)(s), sample)

Parameter (Population)

The collection of all individuals or items under consideration in a statistical study.

Statistic (Sample)

A part of a population from which information is obtained.

Qualitative

Refers to observations that are attributes.

Ex: eye color, blood type, gender, age

Quantitative

refers to observations that are numerical. 

Ex: Height, percentage of seniors with college grants, etc.

Quantitative (Discrete numerical data)

Results from a count

Ex: # of students in the class

Quantitative (Continuous numerical data)

Results from measures of quantity’s

Ex: temp, time, length, weight, mean

Classes 

Categories for grouping data

 Observations

Data pieces

Frequency

The number of observations that fall in a class.

Relative Frequency

The ratio of the frequency of a class to the total number of observations,

Group data table

A table that provides the classes, frequencies, and relative frequencies for a set of data. It describes the frequencies and relative frequencies distributions for the data set.

Single Value 

If data has a very small range, and consists of whole numbers, base each class on a single value.

Width

The difference between the upper and lower cut points of a class

Lower cut point

The smallest value that could go in a cut point grouping class.

Upper cut point

The smallest value that could go in the next higher cut point grouping class. 

Midpoint

The middle of a qualitative class, obtained by taking the average of its lower and upper cut points

Descriptive Measures

• Describes data

Used with mean, median, and mode

Measure of Central Tendency (MCT)

Describes the “typicality“ of the data.

used with: mean, median, and mode

Measure of variation

Describes the spread of the data

used with: Range

Resistant Measures

A measure not affected by the influence of a few observations

used with: IQR and medain

Interquartile range (IQR)

Q1 - Q3