when does correlation occur
when comparing two set of information (one on the x axis and the other on the y)
describe the correlation of this graph
positive correlation = as one variable increases so does the other
describe the correlation of this graph
negative correlation = as one variable increases the other decreases
describe the correlation of this graph
no correlation = no connection between variables
what is an explanatory variable
the variable that is always on the x-axis and independent (eg masses added to a spring)
what is the response variable
the variable always on the y axis and is dependant ( eg the extension of a spring)
what is regression
concerned with finding a linear relationship between two variable where one depends on the other
what is the regression line
the equation of the line of best fit (y = mx + c) from a scatter graph
when is variable reliable
when it is within the given range
when is the variable unreliable
when it is outside the given range
