Bivariate Data 1
Describe the strength for a correlation coefficient of 0.92
Strong
What is the general equation for the regression line
y = mx + c
What is the explanatory variable in a time series graph
Time
A variable that explains the strength of an association in terms of the variation
Coefficient of determination
What is extrapolation.
Predicting data outside the range of values.
What are two identifiable features of a time series graph
-Seasonality
-Trend
-Irregular fluctuations
Justify what happens in a positive association
When the explanatory variable increases, the response variable increases.
If the residual plot shows a U-shaped pattern, the form is...
Non-linear
The total of adding of seasonal indices split up into quarterly intervals is...
4
Calculate the value of the correlation coefficient with an R2 value of 0.25
0.5
The model describes the relationship between temperature and sales using the equation
y = 12.5x - 9.
Interpret the gradient from the equation.
The sales increase by $12.5 per 1 degree Celsius.
Removal of short-term irregularities to improve predictions is..
- smoothing
- deseasonalising
Identify at least 5 steps on how to find the r value using the calculator
MODE, 2, 2, enter x values, enter y values, AC, Shift, 1, 5, 3
Two non-causal explanations between variables
Confounding and common response
What is the average value of a seasonal index
1