Sketch a scatterplot in which the presence of an outlier decreases the observed correlation between...

Step 1
Let the following data be the initial dataset (without any outliers):
[x 1 2 3 4 5 y 1 3 5 7 9]
Since all points lie on the line $[y=2x-1]$, the correlation between those two variables is $[r=1]$ (there is a perfect relationship between the two variables, since there exists a line that passes through all the points, and also, the slope of this line is ${\displaystyle [b_1=2>0]}$ so the association between the two variables is positive which implies that the correlation is also positive).
Let's add the point (6,2) to our initial dataset, so that the data is:
[x 1 2 3 4 5 6 y 1 3 5 7 9 2]
The outlier that we've just added clearly doesn’t belong to the line $[y=2x-1]$
since ${\displaystyle [2\ne q2\cdot 6-1=11]}$.
Therefore, we lost the perfect relationship between the two variables, so the correlation coefficient decreased and the new correlation coefficient is $[r<1]$.
Here is the scatterplot of the given data (outlier is coloured in blue):