Statistics
Histograms

Statistics

Univariate statistics

• Measures of middle (mean, median mode)
• Measures of spread (range and interquartile range)
• Measures of spread (standard deviation)
• Histograms
• Box plots​

Bivariate statistics

• Association between variables
• The effect of outliers on correlation
• Causality
• Interpreting Pearson's correlation coefficient
• Interpolation and extrapolation​​

When data is recorded for a continuous numerical variable, there will be many different values. Therefore the data is grouped into class intervals with lower and upper bounds which can be displayed in a frequency table or a histogram.
A frequency histogram is similar to a column graph, but to account for the continuous nature of the variable, there are no gaps between the columns.