1 / 16

Recap…

Recap…. We need to take spread into account when we give an interval for the population parameter. So far…. Population. Population parameter. Sample. What we’re trying to estimate. Sample statistics. Remember our kiwis…. So far…. Population. What is the median weights of kiwis?.

elton
Download Presentation

Recap…

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. Recap… • We need to take spread into account when we give an interval for the population parameter

  2. So far… Population Population parameter Sample What we’re trying to estimate Sample statistics

  3. Remember our kiwis…

  4. So far… Population What is the median weights of kiwis? Sample Sample statistics What we’re trying to estimate • Take your sample of kiwis • Dot plot • Box plot • Sample statistics…

  5. So far… Population Population parameter Sample What we’re trying to estimate Sample statistics Median weight of kiwis is somewhere between ___ and ___

  6. Samples of size ___ were reliable enough

  7. Distribution of sample medians… The median weight of kiwis was somewhere between ___ and ___ (90% ish of our sample medians)

  8. However in real life … We don’t get to take multiple samples so this process WON’T work We need to find an informal confidence interval for the population median based ON A SINGLE SAMPLE

  9. Our informal interval needs… To take into account both Sample size and spread

  10. More kiwis… For your sample of kiwis: Dot plot Box plot Median

  11. Then Add your SAMPLE MEDIANS TO THE SHEET

  12. Student worksheet Add your IQR (box) TO THE SHEET

  13. Student worksheet Complete Q3 – Q5 on the worksheet

  14. Q3: I notice that the width of the IQR for sample medians when the sample size is 30 is approximately of the width of the population IQR 1/5 WIDTH 0.095 kg-ish (11 mm) WIDTH 0.507 kg-ish (67 mm)

  15. Q4: I notice that the width of the IQR for sample medians when the sample size is 400 is approximately __________ of the width of the population IQR 1/20 WIDTH 0.025 kg-ish (3.5 mm) WIDTH 0.507 kg-ish (67 mm)

  16. Q5: Relationship between the width of the IQR for sample medians of sample size n and the population IR and the sample size… • IQR for sample medians (sample size = n) is approximately of the population IQR • When n = 400 the IQR of the sample medians is approximately ________________ of population IQR • When n = 30 the IQR of the sample medians is approximately ________________ of population IQR

More Related