Final Exam

Question 1

Statistics

Answer 1

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

Question 2

Variable

Answer 2

A characteristic or attribute that can assume different values.

Question 3

Population

Answer 3

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

Question 4

Sample

Answer 4

A group of subjects selected from a population.

Question 5

Bias Sample

Answer 5

Sample is collected in a way that some members were selected is unfair.

Question 6

Descriptive Statistics

Answer 6

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

Question 7

Inferential Statistics

Answer 7

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

Question 8

Qualitative Variables

Answer 8

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

Question 9

Quantitative Variables

Answer 9

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

Question 10

Discrete Variables

Answer 10

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 11

Continuous Variables

Answer 11

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 12

Nominal Level of Measurement

Answer 12

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 13

Ordinal Level of Measurement

Answer 13

Classifies data into categories that can be ranked; however, precise differences between the ranks DON”T exist (Ex. T-shirt size, placings, letter grades)

Question 14

Interval Level of Measurement

Answer 14

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

Question 15

Ratio Level of Measurement

Answer 15

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 16

Random sample

Answer 16

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

Question 17

Systematic sample

Answer 17

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

Question 18

Stratified Sample

Answer 18

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 19

Cluster Sample

Answer 19

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 20

Convenience Sample

Answer 20

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

Question 21

Observational Study

Answer 21

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

Question 22

Experimental Study

Answer 22

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

Question 23

Independent Variable

Answer 23

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

Question 24

Dependent Variable

Answer 24

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

Question 25

Statistic

Answer 25

Characteristic or measure obtained by using the data values from a sample

Question 26

Parameter

Answer 26

Characteristic or measure obtained by using all the data values from a specific population

Question 27

Mean

Answer 27

The sum of the total X values, divided by the total number of values

Question 28

Median

Answer 28

Midpoint of the data array. Symbol is MD

Question 29

Mode

Answer 29

The value that occurs most often in a data set

Question 30

Range

Answer 30

Highest value minus the lowest value

Question 31

Five Number Summary

Answer 31

1. Minimum
2. Q1
3. Median
4. Q3
5. Maximum

Question 32

Outliers

Answer 32

Extreme values

Question 33

Unimodal

Answer 33

Data set that only has 1 value that occurs with greatest frequency

Question 34

Bimodal

Answer 34

Data set that has 2 or more values with the same greatest frequency

Question 35

Multimodal

Answer 35

Data set that has more than 2 values that occur with the same greatest frequency

Question 36

No mode

Answer 36

No data values occur more than once.

Question 37

Margin of Error

Answer 37

Also called the maximum error of the estimate, is the maximum likely difference between the point estimate of a parameter and the actual value of the parameter

Question 38

Normalcdf

Answer 38

Used to find the probability or area under the curve

Question 39

Invnorm

Answer 39

Used to find the z-value (or value in the context of an application problem, such as, finding the length, height, salary, score, or price…)

Question 40

Confidence intervals

Answer 40

90% – 1.65
95% – 1.96
99% – 2.58

Question 41

Confidence Level

Answer 41

Interval estimate of a parameter is the probability that the interval estimate will contain the parameter, assuming that a large number of samples are selected and that the estimation process on the same parameter is repeated

Question 42

The term zx/2(sigma/square root of n) represents the ________.

Answer 42

Margin of error

Question 43

Z-interval

Answer 43

Used when population standard deviation is known.

Question 44

1-probZInt

Answer 44

Used to estimate proportions

Question 45

Z-interval

Answer 45

Used when population standard deviation is known

Question 46

Null Hypothesis

Answer 46

Statistical hypothesis that states that there is no difference between a parameter and a specific value, or that there is no difference between 2 parameters

Question 47

Alternative Hypothesis

Answer 47

Statistical hypothesis that states the existence of a difference between a parameter and a specific value, or states that there is a difference between 2 parameters

Question 48

Type 1 error

Answer 48

Occurs if you reject the null hypothesis when it is true

Question 49

Type 2 error

Answer 49

Occurs if you do not reject the null hypothesis when it is false

Question 50

Independent Samples

Answer 50

Two samples when the subjects selected for the 1st sample in no way influence the way the subjects are selected in the 2nd sample

Question 51

Dependent Samples

Answer 51

Two samples where the selection of subjects for the 1st group in some way influenced the selection of subjects for the other group

Question 52

Significance level

Answer 52

The maximum probability of committing a type 1 error

Question 53

Properties of a good estimator

Answer 53

1. unbiased
2. consistent
3. efficient