CHAPTER 2 Visual description of data to accompany Introduction to business statistics fourth edition by ronald M. Weiers Presentation by Priscilla Chaffe-Stengel Donald n. Stengel o 2002 The Wadsworth Group
CHAPTER 2: Visual Description of Data to accompany Introduction to Business Statistics fourth edition, by Ronald M. Weiers Presentation by Priscilla Chaffe-Stengel Donald N. Stengel © 2002 The Wadsworth Group
l Chapter 2-Learning objectives e Convert raw data into a data array Construct a frequency distribution a relative frequency distribution a cumulative relative frequency distribution Construct a stem-and-leaf diagram Visually represent data by using graphs and charts o 2002 The Wadsworth Group
Chapter 2 - Learning Objectives • Convert raw data into a data array. • Construct: – a frequency distribution. – a relative frequency distribution. – a cumulative relative frequency distribution. • Construct a stem-and-leaf diagram. • Visually represent data by using graphs and charts. © 2002 The Wadsworth Group
ll Chapter 2 -Key terms Data array An orderly presentation of data in either ascending or descending numerical order. Frequency Distribution a table that represents the data in classes and that shows the number of observations in each class o 2002 The Wadsworth Group
Chapter 2 - Key Terms • Data array – An orderly presentation of data in either ascending or descending numerical order. • Frequency Distribution – A table that represents the data in classes and that shows the number of observations in each class. © 2002 The Wadsworth Group
ll Chapter 2 -Key terms Frequency distribution Class- The category Frequency - Number in each class Class limits- Boundaries for each class Class interval-Width of each class Class mark - Midpoint of each class o 2002 The Wadsworth Group
Chapter 2 - Key Terms • Frequency Distribution – Class - The category – Frequency - Number in each class – Class limits - Boundaries for each class – Class interval - Width of each class – Class mark - Midpoint of each class © 2002 The Wadsworth Group
l Sturges rule How to set the approximate number of classes to begin constructing a frequency distribution k=1+3322(l0g10n) 10 where k= approximate number of classes to use and n= the number of observations in the data set o 2002 The Wadsworth Group
Sturges’ rule • How to set the approximate number of classes to begin constructing a frequency distribution. where k = approximate number of classes to use and n = the number of observations in the data set . © 2002 The Wadsworth Group k =1+3322 n 1 0 . (log )