What are the different ways to describe cost behavior?

What are the different ways to describe cost behavior?
• Q2: What process is used to estimate future costs?
• Q3: How are engineered estimates, account analysis, and
two-point methods used to estimate cost functions?
• Q4: How does a scatter plot assist with categorizing a cost?
• Q5: How is regression analysis used to estimate a cost
function?
• Q6: How are cost estimates used in decision making?