A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

For the data shown in the stem-and-leaf plot, what is the effect on the mean and median of adding the value 10 to the data set? A. The mean is decreased by about 0.7 and the median is decreased by 2. B. The mean is decreased by about 0.7 and the median is decreased by 3. C. The mean is decreased by about 1.2 and the median is decreased by 2. D. The mean is decreased by about 1.2 and the median is decreased by

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

    1 Attachment
  2. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Can you count how many numbers are in your "leaf plot" ?

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

    16

  4. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    now count, starting from the top, until you get to number 8 can you do that ?

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

    0?

  6. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes, but that "0" by itself is short for a number. the key tells you how to figure out the number. can you do that ?

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

    the key is 2

  8. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes, 2, and the "0" means your number is 20

  9. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    next, what is the 9th number? (one past the 8th number) ?

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

    a 6

  11. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so what is the 9th number ?

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

    6

  13. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    not just 6. remember to "tag on" the key number

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

    oh... 62?

  15. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    almost. the 2 goes first

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

    so 26

  17. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes. the "median" is the middle number. when we have 16 numbers, 8 numbers are below the median and 8 are above it. to find the median we find the average of the 8th number 20 and the 9th number 26 in other words, the median is (20+26)/2 = what ?

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

    23?

  19. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes. 23 is the median of that data. now to answer the question median of adding the value 10 to the data set? we have to add "10" to the data , and then find the median of those numbers.

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

    honestly... i'm a little confused.

  21. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    to "put 10" into your data you put a 0 in the row with 1 as the "key" number. the 0 goes in front of the other numbers. The 0 goes before 2 5 8

  22. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Here is an example, with the 0 in red

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

    ok

  24. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    now we find the median. Because we added an extra number, we now have 17 numbers the median is the middle number: 8 below the median, 9th number is the median, 8 numbers above. in other words, start at the top and count until you get the 9th number. (don't leave out the 0 we added)

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

    is the 9th number 20? 0 2^

  26. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes. and that is the median of the new data set so we first got 23 as the median now we get 20 as the median the median went down by 3

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

    ok

  28. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    which of the choices *might* be the answer ?

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

    D?

  30. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what does choice D say about the median (I can't read it)

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

    The mean is decreased by about 1.2 and the median is decreased by 3.

  32. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and what about choice B ?

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

    i'm trying to figure out the mean, but i don't know.

  34. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so the answer might be B or D (but not A or C) to decide, we need to find the mean (the average) of the 16 numbers that is a bit painful. Do you know how to do that ?

  35. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you make a list of the numbers by "tagging on" to the front, the key number

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

    i know the simple way lol. add up all the numbers and divide by the amount of numbers. (total divided by 16)

  37. David27
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    d

  38. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    that is how you do it. but first we need to write the numbers 06+08+12+15+18+ etc

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

    i think the total is 61

  40. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    it is more than that. what are the 16 numbers you are using ?

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

    the key.

  42. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    remember the "chart" they show you is using a short cut to write the numbers the first 5 numbers are 06+08+12+15+18 do you see how I got those ?

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

    added 10 to them

  44. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the first two I got from 0 | 6 8 which is "short" for 06 08

  45. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then the next 3 I got from 1 | 2 5 8 which is short for the numbers 12 15 18 and we want to add them up, so the first 5 numbers added together are 06+08+12+15+18 but we need the rest of the numbers.

  46. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what are the numbers you get from the 3rd row ?

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

    10, 10, 10, 16 , 18 and 19

  48. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    almost. but you put a 1 in front. You should be the "key number" in front

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

    so... 20, 20, 20, 26, 28, 29?

  50. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes, and finally the last row

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

    20, 21, 22, 22, 24

  52. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the last row starts with 3 | use the "3" (not a 2)

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

    361/16?

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

    361/16?

  55. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    06+08+12+15+18+20+20+20+26+28+29+30+31+32+32+34 then divide by 16

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

    i got 22.5625

  57. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    when we add 10 the sum goes from 361 to 371 and the average of the 17 numbers is 371/17=

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

    ok, so would the answer be D?

  59. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    the old mean is 22.5625 the new mean (after adding in 10) is 21.8235 the new mean went down by 22.56 - 21.82 = 0.74

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

    i was wrong, the answer is B

  61. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes, choice B is closest. it says the mean goes down by about 0.7

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

    ok, thank you sooooo much. i would have figured it out on my own! :D :D :D :D :D :D :D :D

  63. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    This problem was a lot of work. Good job.

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

    thanks again :D

  65. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yw

  66. 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.