Question Type 5: Describing the correlation Exercises

A scatter diagram shows points lying close to a straight line sloping downward from left to right. Describe the type and strength of the correlation.

Given the data pairs $(1,2)$, $(2,3)$, $(3,5)$, $(4,6)$, $(5,7)$, plot the scatter diagram, draw a line of best fit by eye, and describe the correlation.

Given bivariate data $(1,10)$, $(2,9)$, $(3,7)$, $(4,6)$, $(5,5)$, $(6,3)$, plot the scatter diagram, draw a line of best fit, describe the correlation, and estimate $y$ when $x=4.5$.

The following data relates $x$ and $y$: $(1,3)$, $(2,5)$, $(3,6)$, $(4,8)$, $(5,9)$. Plot a scatter diagram, draw the line of best fit, and use it to estimate $y$ when $x=6$.

A student records hours studied and exam scores: $(2,50)$, $(4,65)$, $(6,75)$, $(8,85)$, $(10,90)$. Plot the scatter diagram, sketch the line of best fit, describe the correlation, and predict the exam score for 7 hours of study.

The data pairs $(1,2)$, $(2,4)$, $(3,6)$, $(4,8)$, $(10,0)$ include an outlier at $(10,0)$. Plot the scatter diagram, draw a line of best fit ignoring the outlier, describe how the outlier affects the correlation, and estimate $y$ for $x=5$ using your line.