2. Examine the arm bones of the two skeletons. Was Grandmother right- or left-handed? How about Grandfather?

He looks ambidextrous but he may also be right handed due to the slight more bone on his right arm.

Explanation:

Its a little hard to tell, my guess is that he was ambidextrous, but his right arm does look slightly more dominant so really it may be his right arm.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.