Which event is being applied when only the denominator changes and not the numerator?

What is the difference between the predicted value and the actual value

What is the common difference for this arithmetic sequence? -6,-2,2,6,10 a.4 b.5 c.3 d.6

Tim tradesman pays $2,000 annually for $125,000 worth of life insurance. what is the cash value of the policy after 10 years? 11,125 13,125 17,800 111,250