Which rotation about its center will carry a regular decagon onto itself

Ascatterplot is produced to compare the size of a school building to the number of students at that school who play an instrument. there are 12 data points, each representing a different school. the points are widely dispersed on the scatterplot without a pattern of grouping. which statement could be true

Annabelle's homework is 75% it took her three hours how long should she estimate it will take her to complete her homework.

Why is causation so much more difficult to prove than correlation?