Week 11 - Introduction, Data, and Graphical presentation

Question 1

What is data?

Answer 1

the facts and figures collected, summarised, analysed, and interpreted

Question 2

What is a data set?

Answer 2

The data collected in a particular study

Question 3

What are elements?

Answer 3

the entities on which data are collected

Question 4

What is a variable?

Answer 4

a characteristic of interest for the elements

Question 5

What is an observation?

Answer 5

The set of measurements collected for a particular element

Question 6

How is the stock return calculated?

Answer 6

Percentage change in the price of the stock

Question 7

How do you calculate the total number of data values in a data set?

Answer 7

the number of elements multiplied by the number of variables

Question 8

What are the scales of measurement?

Answer 8

Scales of measurement refer to how data is categorised, ordered, and quantified.

There are four main types of measurement scales: Nominal, Ordinal, Interval, and Ratio.

Question 9

Data is either?

Answer 9

Qualitative and quantitative

Question 10

What is within quantitative data?

Answer 10

numerical ->
interval, ratio

Question 11

What is within qualitative data

Answer 11

Numerical ->
Nominal, ordinal

Non-numerical ->
Nominal, ordinal

Question 12

What is nominal data?

Answer 12

Data are labels or names used to identify an attribute of the element.

A nonnumeric label or numeric code may be used.

Question 13

Example of nominal data

Answer 13

Students of a university are classified by the school in which they are enrolled using a nonnumeric label such as Business, Humanities, Education, and so on.

Alternatively, a numeric code could be used for the school variable (e.g. 1 denotes Business, 2 denotes Humanities, 3 denotes Education, and so on).

Question 14

What is ordinal data?

Answer 14

The data have the properties of nominal data and the order or rank of the data is meaningful.

A nonnumeric label or numeric code may be used.

Question 15

Example of ordinal data

Answer 15

Students of a university are classified by their course performance using a nonnumeric label such as Distinction, Merit, Pass or Fail.

Alternatively, a numeric code could be used for the class standing variable (e.g. 1 denotes Distinction, 2 denotes Merit and so on).

Question 16

What is interval data?

Answer 16

The data have the properties of ordinal data, and the interval between observations is expressed in terms of a fixed unit of measure.

Interval data are always numeric.

Question 17

Example of interval data

Answer 17

Marianna has an GMAT score of 605, while Kostas has an GMAT score of 490. Marianna scored 115 points more than Kostas.

Question 18

What is ratio data?

Answer 18

The data have all the properties of interval data and the ratio of two values is meaningful.

Variables such as distance, height, weight, and time use the ratio scale.

This scale must contain a zero value that indicates that nothing exists for the variable at the zero point.

Question 19

Example of ratio data

Answer 19

Marianna’s college record shows 36 credits earned, while Kostas’s record shows 72 credits earned. Kostas has twice as many credits earned as Marianna.

Question 20

What is cross sectional data?

Answer 20

data collected at a single point in time or over a short period for multiple subjects (e.g., individuals, companies, countries).

Question 21

Example of cross sectional data

Answer 21

data detailing the number of building permits issued in June 2006 in each of the regions of Italy

Question 22

What is time series data?

Answer 22

data collected over a period of time at regular intervals (e.g., daily, monthly, yearly).

Question 23

Example of time series data

Answer 23

data detailing the number of building permits issued in Tuscany, Italy in each of the last 36 months

Question 24

What are descriptive statistics

Answer 24

are the tabular, graphical, and numerical methods used to summarise data.

Question 25

What are the 3 main categories of descriptive statistics?

Answer 25

1. Measures of Central Tendency (Where is the data centered?) 2. Measures of Dispersion (Variability) (How spread out is the data?) 3. Measures of Shape & Distribution (What is the pattern of data?)

Question 26

Example of descriptive statistics

Answer 26

The manager of Heuson Auto would like to have a better understanding of the cost of parts used in the engine tune-ups performed in the shop. She examines 50 customer invoices for tune-ups. The costs of parts, rounded to the nearest euro, are listed on the next slide.

Question 27

How is a histogram presented?

Answer 27

The variable of interest is placed on the x axis. A rectangle is drawn above each class interval with its height corresponding to the interval’s frequency, relative frequency, or percentage frequency.

Question 28

How to describe a symmetrical histogram?

Answer 28

left tail is the mirror image of the right tail

Question 29

How to describe a skewed left (negative skewness) histogram?

Answer 29

a longer tail to the left

Question 30

How to describe a right skewed (positive skewness) histogram?

Answer 30

a longer tail to the right

Question 31

What does the cumulative frequency distribution show?

Answer 31

the number of items with values less than or equal to the upper limit of each class

Question 32

What does the cumulative relative frequency distribution show?

Answer 32

the proportion of items with values less than or equal to the upper limit of each class

Question 33

What does the cumulative percentage frequency distribution show?

Answer 33

the percentage of items with values less than or equal to the upper limit of each class

Question 34

What are the 3 measures of central tendency?

Answer 34

mean, median, mode

Question 35

What are the 4 measures of dispersion?

Answer 35

standard deviation, variance, range and interquartile range

Question 36

What are the 2 measures of shape and distribution?

Answer 36

skewness and kurtosis

Question 37

What is a scatter diagram?

Answer 37

a graphical presentation of the relationship between two quantitative variables

Question 38

How is a scatter diagram presented?

Answer 38

One variable is shown on the x axis and the other variable is shown on the y axis The general pattern of the plotted points suggests the overall relationship between the variables A trend line is an approximation of the relationship

Question 39

What does a positive relationship trend like look like?

Answer 39

upward sloping line

Question 40

What does a negative relationship trend like look like?

Answer 40

downward sloping line

Question 41

What does a no apparent relationship trend like look like?

Answer 41

horizontal

Question 42

What is statistical inference?

Answer 42

the process of using data obtained from a sample to make estimates and test hypotheses about the characteristics of a population

Question 43

What is the population (part of statistical inference)?

Answer 43

the set of all elements of interest in a particular study

Question 44

What is a sample (part of statistical inference)?

Answer 44

a subset of the population

Question 45

What does statistical analysis often involve?

Answer 45

working with large amounts of data

Question 46

What is usually used to conduct statistical analysis?

Answer 46

Computer software is typically used to conduct the analysis. Statistical software packages such as Microsoft Excel, Minitab and SPSS and are capable of data management, analysis, and presentation