Nayland College  Mathematics Home . Year 9 . Year 10 . Level 1 . Level 2 . L3 Statistics . L3 Maths . L3 Calculus . About . Links 
2 
Investigating data sets Variable types: Quantitative: Which is either Discrete or Continuous The variable to be predicted (response or dependent variable) plotted on the 'y' axis. The explanatory variable (used to make the prediction from) on the 'x' axis. It would be sensible to have one response variable and compare the effect of different explanatory variables. (scope for discussion) Sometimes there will be no 'causation' between the variables so the two variables are associated, and can go on either axis. Experimental data will have the explanatory variable being changed, and the dependent variable being measured. Doing some RESEARCH into your chosen variables is required. Ensure that if there is a possible causation between the variables then the independent (explanatory) variable is 'x' and the dependent variable is 'y' EXPLAIN of why you chose them and reasons for deciding if explanatory, dependent or associated. Investigating Multiple Variable Pairs (scatterplots) using iNZight eg: R = the amount of rainfall per day in Christchurch, and V = the river volume of the Waimakarere river. We can assume that the amount of rainfall will cause changes in the river volume, so the rainfall R is the explanatory variable and the river volume V is the dependant variable. 
Class notes, Class notes More ideas & information on the iNZight tips & tricks page You will be provided with data that has several columns of values: You will need to select appropriate pairs of data sets to establish if a relationship exists. McDonalds data set  Excel version  csv version McDonalds Example: Investigating Variables Class Exemplar: Class Exemplar:

The data set in iNZightWith Quantitative & Qualitative Variables(Discrete & Continuous) 

Investigating a single continuous variable 

Athletes Weight 

Athletes Height 

Investigating a single variable with a subset (by a qualitative variable) 

Athletes Height grouped by gender


Investigating Two continuous variables 

Athletes Height vs Weight


Investigating Two continuous variables (Grouped) 

Athletes Height vs Weight grouped by Gender 

back to top 

Investigating Multiple Variable Pairs (scatterplots) 

1) Load data into iNZight Data set 2) Advanced, Quick Explore, Pairs 3) Select variables
4) Plot


Notice the symmetry, and the degree of relationship seen.Make a VISUAL inspection. This will help you identify possible bivariate combinations to explore furtherMore ideas & information on the iNZight tips & tricks page 