Chapter2 Flashcards
What are the types of data?
Numerical and Categorical
What data is categorised in Categorical data?
Nominal and Ordinal
What data is categorised in Numerical data?
Discrete and Continuous
What is a bar chart used for?
To display the frequency distribution of a Categorical variable.
What type of data does a bar chart use?
Categorical
What is Mode?
The value of a variable that occurs most frequently.
What is a Histogram used for?
To display the frequency distribution of a Numerical variable.
What type of data does a Histogram use?
Numerical
What is a Stem Plot?
The visual display of a numerical data set, an alternate display of a histogram.
What is a Dot Plot?
A number line with each data point marked by a dot.
How do you describe the distribution of a numerical variable?
Shape (symmetric or skewed)
Center (midpoint of the distribution)
spread
What is Mean?
A summary statistic used to locate the centre of a symmetric distribution.
What is Range?
The difference between the smallest and the largest data values
Range = Largest value - Smallest value
What is the Standard Deviation?
The summary statistic that measures the spread of the data values around the Mean
What is Median?
The summary statistic that can be used to locate the centre of a distribution. It is the midpoint of the distribution.
If the distribution is clearly skewed or the there are no outliers, the medium is preferred to the mean as a measure of centre.
What is a Quartile?
A summary statistic that divides an ordered data set into four equal groups.
What does the IQR mean/is used for?
The Interquartile Range gives the spread of the middle 50% of data values in an ordered data set.
The IQR is preferred to the standard deviation as a measure of spread.
What is in the Five-Number Summary?
Minimum value The first Quartile Median The third Quartile Maximum value
How do you calculate for an Outlier?
Lower Fence = Q1 - (1.5xIQR)
Upper Fence = Q3 + (1.5xIQR)
What is a Box Plot?
A visual display of a five-number summary with adjustments made to display outliers separately when they are present.
