Aarrow provides a visual clue to the relationship between two cells by pointing from the precedent cell to the dependent cell.

Tracer

Explanation:

Tracer arrow can be defined as an arrow that is used to show the movement of data from one cell the other.

It provides visual evidence of the relationship between an active cell and other related cells. This means that it provides a visual clue to the relationship between two cells by pointing from the precedent cell to the dependent cell.

Tracer arrows provides information or data about two cells.

a. Precedent cells: Precedent cells are cell that always have a formula contained in them.

b. Dependent cells: Dependent cells are cells that always have a constant value.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .