1 / 24

Estimation

Estimation. By Dr. Hong Zhang For Freshman Engineering Clinic. Purposes. To save cost To save time To give a big picture To make a tentative decision To be the first step for future action. Errors. Based on the knowledge in hand Make reasonable assumptions

leone
Download Presentation

Estimation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Estimation By Dr. Hong Zhang For Freshman Engineering Clinic

  2. Purposes • To save cost • To save time • To give a big picture • To make a tentative decision • To be the first step for future action

  3. Errors • Based on the knowledge in hand • Make reasonable assumptions • 10%~20% or even higher error is normal • New information can and should be used to refine the estimate

  4. Example • Estimate how many chicken are consumed every year in US

  5. Process of Estimate • Collect Data: Population of US is 300 million • Make Assumption: • Average family will consume 2 chicken per month • Average family will have 3 members • Calculation: 2/month * 12 month * (300million/3) =2400 million • Estimate: We consume 2.4 billion chicken per year • Sometime we round up: We consume3 billion chicken per year

  6. Example • Gasoline Consumption To Travel Home • Estimate the amount of gasoline used by Iowa States University students in traveling home and returning during the next Thanksgiving.

  7. Assumptions • Only gasoline for automobiles is considered. Fuel for airplane or train is not considered. • 10% students fly home. The trip to the airport will be by automobile. • Average carpool level is 2 students/car. • Average auto mileage is 20 miles/gallon. • Travel distance will be estimated to be as medium of 50, 150, 250, 350, 450 miles one way. Longer distances will be assumed to fly.

  8. Collected Data • Total 26,500 students in ISU. • Cost of gasoline: $3.59/gal • Distance to airport is 45miles.

  9. Calculations: Travel Distance Estimate

  10. Mileage Total

  11. Total Cost • Gasoline Consumption: (3,166,750miles)/(20miles/gal) = 158,337.5 gal = 1.6*105gal • Gasoline Cost: 158,337.5 gal * $3.59/gal = $568,431.43 = $570k = $0.57 MM

  12. Exercise 1 • Estimate the amount of gasoline used by Rowan University students in traveling home and returning during the next Thanksgiving.

  13. Assumptions • Only gasoline for automobiles is considered. Fuel for airplane or train is not considered. • No student will fly. Assume all students are local or regional. • Average carpool level is 2 students/car. • Average auto mileage is 25 miles/gallon. • Travel distance will be estimated to be as medium of 50, 150, 250, 350 miles one way.

  14. Collected Data • Total 11,392 students in Rowan University. • Cost of gasoline: $2.47/gal (estimate) • Distance to airport is 26 miles.

  15. Calculations: Travel Distance Estimate

  16. Mileage Total

  17. Total Cost • Gasoline Consumption: ( miles)/(25miles/gal) = • Gasoline Cost: gal * $2.50/gal = $

  18. Exercise 1 • Estimate the amount of gasoline used by your class in traveling home and returning during the next Thanksgiving.

  19. Assumptions • Only gasoline for automobiles is considered. Fuel for airplane or train is not considered. • No student will fly. Assume all students are local or regional. • Average carpool level is ? students/car. • Average auto mileage is 25 miles/gallon. • Travel distance will be estimated to be as medium of 50, 150, 250, 350 miles one way.

  20. Collected Data • Total 20 students in your class. • Cost of gasoline: $2.47/gal

  21. Data: Travel Distance

  22. Total Cost • Gasoline Consumption: ( miles)/(25miles/gal) = • Gasoline Cost: ( gal) * $2.47/gal = $

  23. Exercises • Estimate the number of books you will read in your lifetime. • Estimate the total amount of time, mileage and cost you will spend commuting to and from class for this semester. • Estimate the amount of total time spent by the members of this class studying for the class this week. • Estimate the total steps you walk every day and every year. • Estimate the cost of all the food you will consume this semester.

  24. Optional • Estimate the number of gallons of water in Esby pool. • Estimate the paint to paint the outside wall of Rowan Hall. • Estimate how much water you will drink and how much food you will eat in your lifetime

More Related