Lesson 2: Descriptive Statistics

Question 1

Population

Answer 1

the entire collection of people, animals, cells, or other things from which we collect data

Question 2

Parameter

Answer 2

A number that is calculated from an entire population

Question 3

Sample

Answer 3

A subset or group drawn from the population

Question 4

Statistic

Answer 4

A number or quantity that is calculated from a sample of data

Question 5

Descriptive Statistics

Answer 5

Statistics that describe the sample without attempting to generalize the results to other groups or populations

Question 6

Inferential Statistics

Answer 6

Statistics that infer the likelihood that the results can be generalized to the population

Question 7

Measure of Central Tendency

Answer 7

A single value that attempts to describe the central position of a set of data

Question 8

Mean

Answer 8

Average Value

Question 9

Median

Answer 9

Middle Value

Question 10

Mode

Answer 10

Most frequent value

Question 11

Measure of dispersion/variation

Answer 11

A value that describes how the data are dispersed around the measure of central tendency OR the extent to which individual values differ from the mean/median/mode

Question 12

Standard Deviation

Answer 12

On average, how much individual values differ from the mean

Question 13

Variance

Answer 13

How far a set of numbers is spread out from the mean

Question 14

Range

Answer 14

The difference between the largest & smallest value in the data set

Question 15

Interquartile Range

Answer 15

A measure of the “middle fifty” in the data set AKA the difference between first and third quartile of the data

Question 16

Outlier

Answer 16

An observation point that is distant from other observations

Question 17

Frequency

Answer 17

The number of times a value appears in the data set

Question 18

Frequency Distribution

Answer 18

A table or graph that illustrates how frequently each value appears in the data set

Question 19

Normal Distribution

Answer 19

A symmetric, bell-shaped distribution for a continuous variable

Question 20

For a normal distribution.. __ % of observations fall within 1 standard devation, __ % of observations fall within 2 standard devations, and __ % of observations fall within 3 standard devations.

Answer 20

1 = 68% 2 = 95% 3 = 99.7%

Question 21

Confidence Interval

Answer 21

An estimate of the population parameter that will contain the population mean a specified proportion of the time (usually 95% or 99%)

Question 22

Probability

Answer 22

The likelihood that an event will occur

Question 23

What descriptive data is NOT done for nominal data?

Answer 23

Median and Median (we just see frequency distributions and mode)

Question 24

Statistics are sample values. What are their corresponding population values?

Answer 24

Parameters

Question 25

What numbers describe the extent to which individual values differ from the mean?

Answer 25

Measures of dispersion

Question 26

What does a standard deviation of 0 indicate?

Answer 26

All values in the data are the same.

Question 27

In a normal distribution, what percentage of the values fall within two standard deviations of the mean?

Answer 27

95%

Question 28

"What is your religion?" is a nominal scale measure. What measure of central tendency is appropriate to use in this instance?

Answer 28

Mode

Question 29

One hundred participants answer the question, "How many songs did you download last week?" What is the appropriate measure of central tendency to use in this example?

Answer 29

Mean

Question 30

What measure of dispersion is generally reported with the median?

Answer 30

Range

Question 31

What describes the basic objective of descriptive statistics?

Answer 31

To summarize basic findings for the sample

Question 32

What does it tell us if our P-value \< Alpha?

Answer 32

The results are statistically significant.