chapter 1 - Statistics, Data, and Statistical Thinking

Question 1

Statistics

Answer 1

science of data

Question 2

Descriptive Statistics

Answer 2

Describing sets of data using numerical and graphical methods to explore data patterns

Question 3

Inferential Statistics

Answer 3

Drawing conclusions about sets of data based on sampling (need to distinguish between population and sample)

Question 4

units

Answer 4

rows

Question 5

variables

Answer 5

columns

Question 6

Parameter of interest

Answer 6

what your data is focused on

numerical value that you want to draw conclusions about from a sample of data — typically characteristic of a population

ex: average income

Question 7

experimental (observational) unit

Answer 7

object (person, thing, transaction, event) upon which we collect data

ex: individual students/health workers whom we collect data from

Question 8

Variable

Answer 8

numbers or characteristics that can be counted or measured

characteristic of the experimental units

Question 9

Population

Answer 9

A set of experimental units that we are interested in studying

Question 10

Sample

Answer 10

a subset of the units of the relevant population

Question 11

Statistical Inference

Answer 11

estimation, prediction, or other generalization about a population based on information contained in a sample

Question 12

Parameter

Answer 12

number that describes the whole population

any quantity computed from the observations in the population

ex: population mean (average) µ (mu)

average length of a butterfly

Question 13

Statistic

Answer 13

any quantity computed from the observations in the sample

ex: ex: sample mean x̄ (x bar)

ex: the average income for a sample drawn from the U.S. is a sample statistic.

Question 14

Measure of reliability (measure of uncertainty)

Answer 14

statement (usually quantified) about the degree of uncertainty associated with a statistical inference

Question 15

Four Elements of Descriptive Statistical Problems

Answer 15

1. The population or sample of interest
2. One or more variables that are to be investigated
3. Tables, graphs, or numerical summary tools
4. Identification of patterns in the data

Question 16

Five Elemental of Inferential Statistical Problems

Answer 16

1. The population of interest
2. One or more variables that are to be investigated
3. A sample
4. The inference about the population based on information contained in the sample
5. A measure of reliability for the inference

Question 17

Quantitative data (numerical data)

Answer 17

data that can be counted and measured in numeric values

ex: temperature
unemployment rate
test scores
number of female executives

Question 18

Qualitative data

Answer 18

measurements that cannot be recorded on a numerical scale; can only be classified into one of a group of categories

ex: zip codes
“yes/no”

Question 19

Representative sample

Answer 19

exhibits characteristics typical of those possessed by the population of interest

Question 20

Stratification

Answer 20

splitting population into strata and then a random subsample is taken from each stratum

SUB-SAMPLE EACH GROUP

Question 21

cluster sample

Answer 21

a sample in which each population unit belongs to a cluster, and the clusters are sampled

SAMPLE GROUPS

Question 22

Systematic sample

Answer 22

every kth unit in the population

selected according to a random starting point but with a fixed, periodic interval

divide population size by desired sample size

Question 23

Randomization

Answer 23

• selection is fair
• protects against biased samples
• help represent all the features of the population

Question 24

Sampling variability (sampling error but no error has taken place)

Answer 24

sample-to-sample differences in the values of the variables