Stats 1045 Vocab 2

Question 1

Histogram

Answer 1

A graph, often using blocks constructed above class intervals, used to summarize data.

Question 2

Class Intervals

Answer 2

Ranges of values along the x-axis of a histogram above which blocks are drawn.

Question 3

Distribution Tables

Answer 3

A listing of the number or percentage of subjects corresponding to each class interval, for all intervals in a data set.

Question 4

EndPoint

Answer 4

A rule for a histogram that decides into which class intervals subjects are placed if their value is on the boundary between two intervals.

Question 5

Density Scale

Answer 5

A vertical scale used on histograms defined as ‘percent of subjects per unit.’ (Where the unit is whatever is appropriate for the data.)

Question 6

Variable

Answer 6

The general term for a characteristic that changes from subject to subject in a study

Question 7

Quantitative Variables

Answer 7

Variables that are measured by giving a number value (like height, income, age).

Question 8

Qualitative Variables

Answer 8

Variables that are described by descriptive words or phrases for each subject (like religion, profession, etc.)

Question 9

DIscret Variables

Answer 9

A quantitative variable with values that can only differ by fixed amounts.

Question 10

Continuous Variable

Answer 10

A quantitative variable with values that can differ by arbitrarily small amounts.

Question 11

Cross-Tabulation

Answer 11

A tabular way to control for a confounding factor, where separate distribution tables are made for different values of the confounding factor.

Question 12

Average list of numbers

Answer 12

The sum of all numbers in a list, divided by how many number entries there are.

Question 13

Average of a Histogram

Answer 13

The value where the histogram balances when supported at that point.

Question 14

Meridian of a Histogram

Answer 14

The value for which half of the area of the histogram is to its left, and half to its right.

Question 15

Cross-Sectional Study

Answer 15

A study when different subjects are compared to each other at one point in time.

Question 16

Longitudinal Study

Answer 16

A study when the same subjects are followed over time and compared with themselves at different points of time.

Question 17

Standard Deviation

Answer 17

A measure that represents the spread of a list around its average. More specifically, the r.m.s size of the deviations of the list from the average.

Question 18

Standard Units

Answer 18

A scale that measures how many standard deviations values in a list are away from the average.

Question 19

Normal Approximation

Answer 19

The procedure of replacing an original histogram with a normal curve in standard units and using the normal curve to find areas.

Question 20

Percentiles

Answer 20

Used to summarize histograms, these are values of the variable for which a given percentage of the data is smaller than the value.

Question 21

Interquartile Range

Answer 21

A measure of spread used on a histogram found by the following subtraction: (75th percentile) - (25th percentile).

Question 22

Normal Curve

Answer 22

A curve discovered around 1720 by Abraham de Moivre, with a “bell-shaped” histogram that is centered and symmetric about 0