A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Estimate the population of bacteria at 9 hours. Time (hours) 0 1 2 3 4 5 6 Population (1000s) 5.1 3.03 1.72 1.17 1.38 2.35 4.08

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @xapproachesinfinity

  2. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    did you try drawing this!

  3. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    to see what kind of graph it might be

  4. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No, i don't know where to start. But i do have to show my work

  5. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    well look for an online plotter put all of those points then post the picture you got here

  6. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok one second

  7. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    this looks like a polynomial to me!

  8. mathmate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    When the numbers are given in equal intervals, another way is to calculate the differences of the given numbers. If the differences are not constant, it means that the function does not represent a straight line. However, you can calculate the differences of the previously calculated differences. If the second difference is constant, the function is a quadratic. You can then continue the sequences to find f(9).

  9. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How do i keep it going to find the answer for 9 hours though

  10. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    the second difference is constant 0.76 so it really is a quadratic

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so how do we use the quadratic to find the answer? im confused and need to show my work

  12. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    there is a different method then the sequence f(x)=ax^2+bx+c f(0)=5.1 f(1)=3.03 f(2)=1.17 you got 3 equation in terms of a,b,c solve for them

  13. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    if you got the equation you plug 9 for f(9)

  14. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    A=3.8 B=-2.45 and C=5.1

  15. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    no no

  16. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I had to find that in the question previous to this one

  17. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Are we doing it differently because we are plugging in the 9?

  18. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    you have to find a,b , and c plug 0 for one equation 1 for the second 2 doe the third system of three equation

  19. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    f(0)=5.1=c actually c is good!

  20. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    how did you find b and a

  21. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    f(1)=3.03=a+b f(2)=1.72=4a+2b

  22. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    oh i forgot c a+b+c=3.03 4a+2b+c=1.72

  23. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    c=5.1

  24. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok i've written what we have so far

  25. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    solve that for a and b

  26. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    4a+2b=-3.38?

  27. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    yes! now you have two equation solve for a and b

  28. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    i got a=0.38 b=-2.45

  29. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thats what i have

  30. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    so we have f(x)=0.38x^2-2,45x+5.1

  31. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    http://prntscr.com/7odnai looks like the shape we have before

  32. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    plug in 9 for f(9)

  33. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How do i do that though ? thats where i get lost

  34. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    f(9)=0.38 (9)^2-2.45(9)+5.1

  35. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    you just replace x by 9

  36. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok, one sec im gonna calculate

  37. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    F= 30.78-22.05+5.1

  38. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    we need final value what is it?

  39. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    13.83

  40. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    yes!

  41. xapproachesinfinity
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    that's the number of bacteria after 9hours in thousands

  42. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So thats our final answer 13.83? :)

  43. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.