Which of the following scatterplots best illustrates an outlier in the $y$-direction?

• A. A scatterplot where one point is far to the right of the others horizontally, but at the same vertical level.
• B. A scatterplot where most points follow a linear trend, but one point is far above the others vertically.
• C. A scatterplot where all points are evenly spread along a straight line.
• D. A scatterplot where all points are clustered tightly in the center.

Answer: (B)

Verified step by step guidance

1. Understand what an outlier in the y-direction means: it is a data point whose y-value (vertical position) is significantly different from the other points, while its x-value (horizontal position) may be similar or within the range of other points.
2. Review each scatterplot description and identify the position of the unusual point relative to the others:
3. For the first option, a point far to the right horizontally but at the same vertical level means the outlier is in the x-direction, not the y-direction.
4. For the second option, a point far above the others vertically while most points follow a linear trend indicates an outlier in the y-direction.
5. The third and fourth options describe points that are either evenly spread along a line or tightly clustered, which do not represent outliers in the y-direction.