Chapter 2 - Data Presentation Flashcards
in statistics, do all data come in the form of numbers
no
what are the two groups main groups that data can be split into
- categorical data
- numerical data
what are categorical data also known as
nominal data
what is categorical data
it is data that do not take numerical data
what are examples of numerical data
gender, male or female
what is ordinal data
ordinal data is a type of data that can be placed in different categories of observations and used to provide order
what are examples of ordinal data
- education level [ high school, bachelor’s degree, master’s, PHD]
- Customer Satisfaction Rating [ very unsatisfied, unsatisfied, neutral, satisfied, very satisfied]
what is numerical data
numerical data is based upon the ability to measure specific items in the population or survey sample to determine a specific amount or quantity
what is numerical data also referred to as
quantitative data
what is discrete data
items that can be counted and then listed out [ number of …..]
what is continuous data
continuous data is data that can take any value over a range [ not restricted to whole numbers] usually the data is measurable
what is a example of continuous data
- heights of students in a class
what is cardinal data
cardinal data is data can be directly measured and is the most relevant for quantitative analysis
what are examples of cardinal data
temperature [ 20deg, 25 deg, 30deg]
what are bar charts
a bar chart is the simplest type of chart to draw and read
what is the purpose of a bar chart
it is used to compare frequencies and values of different categories or groups
what is different and important when drawing a bar chart
- the length of the bar indicates the size of the category
- in the bar chart, only the y-axis has a scale
- the x- axis, on the other hand, is divided into categories
how is a histogram used
a histogram is used to show the distribution of variables
[ in presentational terms, there are no gaps between the columns representing the different categories]
what is a line chart
a line chart is an effective way of visualising trends in data over time
what is a example when using a line chart is useful
- for example, the sales of a company by month, over a six-month period
what is a pie chart
- we draw a circle to represent percentage of the total of all categories
- given that a circle has 360 degrees, we simply apportion the circle to the components categories according to their relative importance
how do we calculate the median
if a set of data is arranged in order of magnitude, the middle value which divides the set into two equal groups, is the median
what is mode
mode is the item which occurs most frequently
what is the formula to finding median
if N is the number of values in the dataset
[N +1]/2 => Median
