Exam 1

Question 1

Statistics

Answer 1

Is the science of conducting studies to collect, organize, analyze, and draw conclusions from data.

Question 2

Data

Answer 2

Values (measurements/observations) that the variables can assume.

Question 3

Data value/datum

Answer 3

What each value in the data set is called.

Question 4

Random variable

Answer 4

Variables with their values determined by chance.

Question 5

Population

Answer 5

Consists of all subjects (human or otherwise) that are being studied.

Question 6

Sample

Answer 6

A group of subjects selected from a population.

Question 7

Descriptive Statistics

Answer 7

Consists of the collection, organization, summarization, and presentation of data.
(Describes, data can be shown in graphs, tables, etc.)

Question 8

Inferential Statistics

Answer 8

Consists of generalizing from samples to populations, performing estimations & hypothesis tests, determining relationships among variables, and making predictions.
(Statistician tries to make inferences)

Question 9

Qualitative Variables

Answer 9

Variables that have distinct categories according to some characteristic or attribute (Ex. hair color, drink brand, Jersey #, gender, religion, geographic location)

Question 10

Quantitative Variables

Answer 10

Variables that can be counted or measured (Ex. age, height, weight, body temp, # of frogs)

Question 11

Discrete Variables

Answer 11

Assume variables that can be counted and assigned values like 0,1,2,3, etc. (Ex. # of frogs in a contest, # of children in a family, calls received in a month)

Question 12

Continuous Variables

Answer 12

Can assume an infinite # of values between any 2 specific values. They are obtained by measuring and often contain fractions and decimals. (Ex. distance a frog jumps, temp of a frog)

Question 13

Nominal Level of Measurement

Answer 13

Classifies data into mutually exclusive (nonoverlapping) categories in which no order or ranking can be placed on the data (Ex. classifying people by zip codes, political party, religion, or marital status)

Question 14

Ordinal Level of Measurement

Answer 14

Classifies data into categories that can be ranked; however, precise differences between the ranks doesn’t exist (Ex. T-shirt size, placings, letter grades)

Question 15

Interval Level of Measurement

Answer 15

Ranks data and precise differences between units of measure do exist; however, there is no meaningful zero (Ex. IQ score, temperature)

Question 16

Ratio Level of Measurement

Answer 16

Possess all the characteristics of interval measurement and there is a true zero. Also, true ratio exists when the same variable is measured on two different members of the population (Ex. scales used to measure weight, height, and area) (Ration Ex. one person can lift 200lbs. one person can lift 100lbs. this would be a 2:1 ratio between them)

Question 17

Random sample

Answer 17

Sample where all members of the population have an equal chance of being selected.

Question 18

Systematic sample

Answer 18

Sample is obtained by selecting every kth member of the population (Ex. picking every 5th person in line)

Question 19

Stratified Sample

Answer 19

Sample obtained by dividing the population into subgroups/strata according to some characteristic relevant to the study (there can be several subgroups) subjects are then selected at random from each subgroup.

Question 20

Cluster Sample

Answer 20

Obtained by dividing the population into sections/Clusters and then selecting one or more clusters at random and using all the members of the cluster(s) as the sample. (Used when the population is too large or involves multiple locations)

Question 21

Convenience Sample

Answer 21

Researcher uses subjects that are convenient (Ex. interviewing people who walk into the mall)

Question 22

Observational Study

Answer 22

Researcher merely observes what is happening or what has happened in the past and tries to draw conclusions based on these observations.

Question 23

Experimental Study

Answer 23

Researcher manipulates one of the variables and tries to determine how the manipulation influences other variables

Question 24

Independent Variable

Answer 24

The variable that is being manipulated by the researcher; independent variable is AKA the explanatory variable. This is the x-axis.

Question 25

Dependent Variable

Answer 25

Resultant variable or the outcome variable. This is the y-axis

Question 26

Treatment Group

Answer 26

Group that received a specific instruction

Question 27

Control Group

Answer 27

Group that doesn’t receive specific instruction

Question 28

Categorial Frequency Distribution

Answer 28

Used for data that can be placed in specific categories (nominal or ordinal-level data) (Ex. political affiliation, religious affiliation, field of study)

Question 29

Grouped Frequency Distribution

Answer 29

Range of data must be grouped into classes that are more than 1 unit in width.

Question 30

Ungrouped Frequency Distribution

Answer 30

Using single data values for each class

Question 31

Bell-shaped Distribution

Answer 31

Has a single peak and tapers off at either end. (Approx. symmetric.)

Question 32

Uniform

Answer 32

Flat or rectangular

Question 33

J-shaped

Answer 33

Has a few data values on the left side and increases as one moves right

Question 34

Reverse J-shaped

Answer 34

Opposite of the j-shaped distribution

Question 35

Positively or right-skewed

Answer 35

The peak of the distribution is to the left and the data values taper off to the right.

Question 36

Negatively or left-skewed

Answer 36

Data values are clustered to the right and taper off to the left

Question 37

Unimodal

Answer 37

Distributions with 1 peak

Question 38

Bimodal

Answer 38

Distribution has 2 peaks of the same height

Question 39

U-Shaped

Answer 39

Distribution is shaped like a “U”

Question 40

Histogram

Answer 40

A graph that displays the data by using contiguous vertical bars (unless the frequency of a class is 0) of various heights to represent the frequencies of the class

Question 41

Frequency Polygon

Answer 41

Graph that displays data by using lines that connect points plotted for the frequencies at the midpoints of the class. The frequencies are represented by the heights of the points

Question 42

Ogive

Answer 42

A graph that represents the cumulative frequencies for the classes in a frequency distribution