Bivariate Data Revision Flashcards

Vocabulary flashcards covering key statistical terms, linear regression, two-way tables, and seasonal indices based on the revision material.

Linear Regression Model ($T$ and $n$)

A mathematical model fitted to quantitative bivariate data to represent the linear relationship between daily temperature in degrees Celsius ($T$) and the number of icy poles sold ($n$).

Correlation Coefficient ($r$)

A statistical value that indicates the direction and strength of the linear association between daily temperature ($T$) and icy poles sold ($n$).

Coefficient of Determination ($r^2$)

A statistical metric calculated to four decimal places that gives the proportion of variation in the dependent variable explained by the variation in the independent variable.

Residual Plot Point $(12, 6.56)$

A data point on a residual plot indicating that at an observed temperature of $12\text{ degrees Celsius}$, the actual number of icy poles sold was $6.56$ units higher than predicted by the linear regression model.

Electricity vs Temperature Variables

A quantitative bivariate dataset where Temp in degrees Celsius is represented by $x$ and Electricity usage in $\text{kWh}$ is represented by $Y$.

Gradient ($a$)

In the linear model relating electricity usage to temperature, the parameter $a$ represents the rate of change of electricity consumption in $\text{kWh}$ per unit change in temperature.

Y-intercept ($b$)

In the linear model relating electricity usage to temperature, the parameter $b$ represents the baseline electricity consumption in $\text{kWh}$ when the temperature is $0\text{ degrees Celsius}$.

Two-Way Categorical Frequency Table

A summary grid used to organize bivariate categorical data by classifying total responses into categories such as In favour or Against regarding Cats and Dogs.

Quarterly Seasonal Index Table

A structured table displaying quarterly seasonal indices across multiple years (2021–2023) to measure recurring quarterly variation relative to the average.

Deseasonalised Data

Time series values calculated by dividing actual observed measurements (such as Hobart quarterly rainfall in $\text{mm}$) by their corresponding seasonal indices to remove underlying seasonal effects.

Seasonal Index Sum Rule

The property that the sum of all seasonal indices across four quarters in a year must equal $4.0$, used to calculate missing quarterly indices when given the remaining quarters.

Deseasonalised Rainfall Formula

The mathematical ratio calculated as $\text{Deseasonalised Rainfall} = \frac{\text{Actual Rainfall}}{\text{Seasonal Index}}$, used to adjust recorded rainfall (e.g., $33\text{ mm}$ with an index of $1.1$).

Percentage Column Chart Grid

A graphing grid with a vertical axis scaled from $0$ to $100$ used to construct comparative column charts for categorical percentage distributions.

Time Series Plot Grid

A coordinate axes grid with a y-axis from $0$ to $60$ and an x-axis from $0$ to $12$, used for plotting seasonal and deseasonalised rainfall trends across 12 quarters.