1 / 12

Measures of CentralTendency

Measures of CentralTendency. What is an average OR arithmetic mean?. Activity. Where do we see averages(means) ?. How are averages(means) used ?. How do we calculate averages (means) ?. Add the numbers of the data set together and divide by the number of data points .

tamar
Download Presentation

Measures of CentralTendency

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. Measures of CentralTendency

  2. What is an average OR arithmetic mean? Activity

  3. Where do we see averages(means)? How are averages(means) used?

  4. How do we calculate averages (means)? Add the numbers of the data set together and divide by the number of data points. During the first half, Harvey ran the following number of yards for his 5 carries: 9        11      16      4      10 What is the average (mean) number of yards per carry that Harvey ran in the first half? Data set Data points 9 + 11+ 16 + 4 + 10 = 10 5

  5. A Closer Look at Averages (Means) . . . The person’s temperature is fine. Agree Disagree

  6. A Closer Look at Averages (Means) . . . 500 Guests How would you determine the average(mean) wealth of the guests staying at the Ritz Hotel on a particular day? Would the average(mean) be affected if Bill Gates stayed at the hotel? 62.7 Billion Extreme values affect the mean.

  7. Comparison of Averages(Means) with an Extreme Value 499 Guests each having a wealth of $1,000,000 and Bill Gates having a wealth of $62.7 Billion 500 guests - each having a wealth of $1,000,000 Mean: $1,000,000 Mean: $126,398,000 62,700,000,000 499,000,000 63,199,000,000

  8. What is a median? The middle number (in a sorted list of numbers). Example: Cost of Dinners at a Restaurant: 13 15 18 21 11 12 10 Middle Sort 1 10 11 12 13 15 18 21 2 Middle What does the median cost of dinners tell us?

  9. Finding the median The restaurant adds a new dinner item to the menu: 10 11 12 13 14 15 18 21 Middle If the number of data points is odd, the median is the mean (the average) of the middle two values: • The median does not have to be a value in the dataset. • The position of the median can be found by: • (the number of data points + 1) ÷ 2 13+14 = 13.5 2

  10. Practice Finding the Median What is the median points scored in the Falcons 2013 regular season? 40 27 27 30 24 23 30 19 27 23 24 23 20 34 31 17 17 19 20 23 23 23 24 24 27 27 27 30 30 31 34 40 Median: 25.5 • Sort • Find position of middle value(s): (Number data points + 1) • 2 • If necessary, average middle values

  11. What is the mode? The mode is the number repeated most often. Example: What is the mode of the points scored in the Falcons 2013 regular season? 40 27 27 30 24 23 30 19 27 23 24 23 20 34 31 17 Do you think a data set could have more than one mode? Do you think every data set has a mode?

  12. Toying with Measures Activity Calculate the mean, median, and mode of purchasing the original 6 toys. Make predictions about whether the purchase or return of toys will cause the measures of central tendency to increase or decrease. Calculate the mean, median, and mode of the purchased/returned toys. Discuss. Do the results match your predictions?

More Related