Lectures Applied statistics for business: Chapter 2 - ThS. Nguyễn Tiến Dũng

Lectures "Applied statistics for business - Chapter 2: Tabular and graphical presentations" provides students with the knowledge: Summarising data for a categorical variable, summarising data for a quantitative variable, summarising data for two variables using tables,... Invite you to refer to the disclosures.
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Lectures Applied statistics for business: Chapter 2 - ThS. Nguyễn Tiến Dũng Chapter 2TABULAR AND GRAPHICAL PRESENTATIONS MBA Nguyen Tien Dung School of Economics and Management Website: https://sites.google.com/site/nguyentiendungbkhn Email: dung.nguyentien3@hust.edu.vnMain Contents2.1 Summarising Data for a Categorical Variable2.2 Summarising Data for a Quantitative Variable2.3 Summarising Data for Two Variables Using Tables2.4 Summarising Data for Two Variables Using Graph Displays2.5 Data Visualisation: Best Practices In Creating Effective© Nguyễn Tiến Dũng Applied Statistics for Business 22.1 SUMMARISING DATA FOR A CATEGORICALVARIABLE● Frequency Distribution● Relative Frequency and Percent Frequency● Bar Charts and Pie Charts© Nguyễn Tiến Dũng Applied Statistics for Business 3Frequency Distribution Table ● A tabular summary of data showing the number (frequency) of items in each of several nonoverlapping classes.© Nguyễn Tiến Dũng Applied Statistics for Business 4Relative Frequency and Percent FrequencyDistributions© Nguyễn Tiến Dũng Applied Statistics for Business 5Bar Chart and Pie Chart© Nguyễn Tiến Dũng Applied Statistics for Business 62.2 SUMMARISING DATA FOR A QUANTITATIVEVARIABLE● Frequency Distribution● Relative Frequency and Percent Frequency Distributions● Dot Plot● Histogram● Cumulative Distributions● Stem-and-Leaf Display© Nguyễn Tiến Dũng Applied Statistics for Business 7Frequency Distribution ● Number of nonoverlapping classes ● By a formula ● On purpose: 3-20 ● Width of each class ● The class lower and upper limits© Nguyễn Tiến Dũng Applied Statistics for Business 8© Nguyễn Tiến Dũng Applied Statistics for Business 9● Step 1: Determining the number of classes ● Xmin = 12; Xmax = 33  Max – Min = 33 – 12 = 21. ● Select: k = 4; or k = 5  Textbook: k = 5● Step 2: Determining the class width ● Normally: w = (Max – Min)/ k ● Here, textbook: Min (the lower bound of the first class) = 10; Max = 35  w = (35-10)/5 = 5● Step 3: Allocating the observed data into classes ● Sorting the data set in the ascending order ● Allocating● Step 4: Establishing the frequency table© Nguyễn Tiến Dũng Applied Statistics for Business 10Principles of allocating the data points into classes● No overlapping cases: one observation must belong to only one class● If an observation belongs to the upper bound of one class, put it into the next class ● Class 1: 10 – 15 days ● Class 2: 15 – 20 days ● X3 = 15 -> Class 2© Nguyễn Tiến Dũng Applied Statistics for Business 11Open-ended classes ● An example: ● Audit days: Working years ● Less than 15 for a company ● 15-19 ● Less than 1 ● 20-29 years ● 29-34 ● 1 – 3 years ● 35 and more ● 3 – 5 years ● More than 5 years© Nguyễn Tiến Dũng Applied Statistics for Business 12Dot Plot© Nguyễn Tiến Dũng Applied Statistics for Business 13Histogram = Frequency Distribution Chart© Nguyễn Tiến Dũng Applied Statistics for Business 14Different Levels of Skewness© Nguyễn Tiến Dũng Applied Statistics for Business 15Cumulative Distributions© Nguyễn Tiến Dũng Applied Statistics for Business 16Ogive = Cumulative Frequency Chart© Nguyễn Tiến Dũng Applied Statistics for Business 172.3 EXPLORATORY DATA ANALYSIS: THE STEM-AND-LEAF DISPLAY ● Number of questions answered correctly on an aptitude test ● N = 150© Nguyễn Tiến Dũng Applied Statistics for Business 18Stem and Leaf Diagram© Nguyễn Tiến Dũng Applied Statistics for Business 192.4 CROSSTABULATIONS AND SCATTEREDDIAGRAMS ● Crosstabulation ● Simpson’s Paradox ● Scatter Diagram and Trendline© Nguyễn Tiến Dũng Applied Statistics for Business 20