Statistics and Data Representation

Comprehensive vocabulary flashcards covering basic statistics, table data analysis, histograms, cumulative frequency, and scatter plot correlations based on lecture notes.

Mode

The most occurring value in a data set.

Median

The middle value of a data set. The first step to find it is to arrange data in increasing order.

Mean (Average)

The sum of all values divided by the total count ($n$).

Range

The difference between the maximum and minimum values in a data set ($Range = \text{Max} - \text{Min}$).

Cutting Method

A technique used to find the median specifically for raw data, which cannot be used for table data.

Median Formula (Table Data)

The formula used to find the position of the median: $\frac{n+1}{2}$ term.

Summation Symbol ($\text{Σ}$)

A mathematical notation representing 'total' or 'summation'.

Mean Formula for Table Data

Calculated by dividing the sum of the product of frequency and values by the total frequency: $\frac{\text{Σ} fx}{\text{Σ} f}$.

Modal Class

In a range table, the interval or class that contains the highest frequency.

Midvalue of $x$

The middle point of a range used as the $x$ value for calculating the mean in grouped data tables.

Frequency Density ($FD$)

Used on the $y$-axis for histograms with different class widths, calculated as $\frac{\text{Frequency}}{\text{Class Width}}$.

Frequency Polygon

A graph made by joining the midpoints of the tops of each bar in a histogram; the lines do not need to be joined to the $x$-axis at the ends.

Area Under a Frequency Density Graph

Represents the number of items or total frequency for a specific range.

Upper Quartile ($UQ$)

The value corresponding to the $\frac{3}{4} n^{\text{th}}$ term on a cumulative frequency graph.

Lower Quartile ($LQ$)

The value corresponding to the $\frac{1}{4} n^{\text{th}}$ term on a cumulative frequency graph.

Interquartile Range ($IQR$)

The difference between the Upper Quartile and the Lower Quartile ($UQ - LQ$).

Percentile

For a $k^{\text{th}}$ percentile, find the value at the corresponding position on the $y$-axis: $\frac{k}{100} \times n$.

Line of Best Fit

A trend line drawn through scatter plot points that balances the number of points on each side and represents the general trend.

Positive Correlation

A relationship in a scatter plot where both variables tend to increase together.

Negative Correlation

A relationship in a scatter plot where one variable increases as the other decreases.

Zero Correlation

When there is no visible relationship or trend between the points on a scatter plot.

Pictogram

A data representation method that uses symbols to represent a specific value or quantity of items.