An estimated demand curve does not necessarily match actual data perfectly because A. it is not possible to accurately calculate the coefficients of the curve. B. demand is unpredictable. C. some factors that are not measured or observed may affect the curve. D. the random error term has too large of a range.

C. some factors that are not measured or observed may affect the curve.

Explanation:

a lot of unforeseen circumstances might occur. these occurrences would not be measured in the estimated demand curve. this would lead to the estimated demand curve not matching the actual demand curve.

for example, the factors affecting the demand for bread are ; price, income, price of a substitutes. these are included in estimating the demand curve for bread. Assume that a study comes out stating that bread is harmful to the health.this reduces the demand for bread. this study wasn't anticipated and included in estimating the demand curve. as a result, the actual data would differ from the estimated data  

i'ts proportional. if the inflation rate is 12% for example, the cpi will be 12% less.

hope it ,

bioteacher101

since the options are not listed, when you are working on your budget you should also add water, tv, internet, miscellaneous and your 'fun' money for in your budget. when budgeting, you need to allow for fun money, and mis/accidental money so that you stick to the budget and not go crazy because you feel strapped to the budget.