Question

(a) a yoga instructor collected student data. he found that students who had less sleep did not tend to have a greater range of motion during class. what can he conclude?

there is no correlation between amount of sleep and range of motion.
there is a correlation between amount of sleep and range of motion. there may or may not be causation. further studies would have to be done to determine this.
there is a correlation between amount of sleep and range of motion. there is probably also causation. this is because there is likely an increase in the range of motion with an increase in the amount of sleep.

Explanation:

The instructor found no tendency for less sleep to relate to greater range of motion, meaning there is no observed correlation between the two variables. Correlation requires a consistent relationship (positive or negative), which is absent here.

Answer:

There is no correlation between amount of sleep and range of motion.