Ch.4 Correlation

Question 1

what is bivariate data?

Answer 1

data with pairs for two variables

Question 2

how would bivariate data be plotted in a graph?

what would be on the x- and y- axes?

Answer 2

the x-axis would have the independant or explanatory variable which is controllable

the y-axis would have the dependant or response variable which is measured

Question 3

what does correlation describe?

Answer 3

the nature of the linear relationship between two variables

Question 4

when two variables are correlated how would you determine whether they have a causal relationship?

Answer 4

consider the context of the questions and use common sense

Question 5

what does a line of best fit on a graph do?

Answer 5

approximates the relationship between variables

Question 6

what is a regression line on a graph?

Answer 6

a more technical line of best fit

Question 7

how is a line of regression written?

Answer 7

in the form y = a + bx where a is the y-intercept and b is the gradient

Question 8

when should the regression line not be used to make predictions?

Answer 8

for data outside the range of given data

Question 9

how would you interpret the gradient of a line of regression?

Answer 9

talk about how the gradient was calculated with context

e.g. if a gradient was 1.8
x increased by 10 every time y increased by 18

Question 10

how would you justify using a line of regression?

Answer 10

if there is a correlation between the linear relationship on the graph