1 / 12

1-7 Variance & Standard Deviation

1-7 Variance & Standard Deviation. Investigation…. Let’s take a look at the following two sets of notebook grades: A: {59, 60, 60, 62, 63, 64, 67, 68, 68, 69} B: {59, 63, 64, 64, 64, 64, 64, 64, 65, 69} Create a dotplot for each set of data…. 59 61 63 65 67 69.

hallam
Download Presentation

1-7 Variance & Standard Deviation

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. 1-7 1-7Variance &Standard Deviation

  2. 1-7 Investigation…. Let’s take a look at the following two sets of notebook grades: A: {59, 60, 60, 62, 63, 64, 67, 68, 68, 69} B: {59, 63, 64, 64, 64, 64, 64, 64, 65, 69} Create a dotplot for each set of data….

  3. 1-7 59 61 63 65 67 69 59 61 63 65 67 69 Set A Set B Mean: 64 64 Range: 10 10

  4. 1-7 Measures of Spread • Mean, Median, and sometimes mode are used as measures of the “center” of data • Deviation, Variance, and standard deviation are all measures of spread . These are used to measure how a set of data is distributed in relation to the mean.

  5. 1-7 Deviation • Deviation is the difference between each piece of data and the mean • A positive deviation means that the piece of data is greater than the mean • A negative deviation means that the piece of data is less than the mean

  6. 1-7 Variance • Variance is found by finding the sum of the squares of the deviations of each term • Then dividing by one less than the number of terms

  7. 1-7 Standard Deviation • Standard Deviation is found by finding the square root of the variance.

  8. 1-7 Example with a set of data • Let’s review the two sets of notebook grades: • A: {59, 60, 60, 62, 63, 64, 67, 68, 68, 69} • B: {59, 63, 64, 64, 64, 64, 64, 64, 65, 69} • Calculate the Standard Deviation for both sets of data…

  9. 1-7 Compare the results • Set A: Standard Deviation = 3.77 • Set B: Standard Deviation = 2.4

  10. 1-7 59 61 63 65 67 69 59 61 63 65 67 69 Revisit data sets: Set A Set B S.D. = 2.4 S.D. = 3.77

  11. 1-7 Population Var & S.D. • If data represents population and not a sample, you must use n instead of n-1 in variance formula

  12. 1-7 How to find SD in your calculator…

More Related