Compare and contrast five quantitative ways to describe the composition of solutions

100 points, hi, i’m not sure how to get the equation from the graph and table.

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

Wrote and expression for the difference of p and 4