1. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
http://www.mathsisfun.com/data/standard­deviation.html#WhySquare

2. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots
The weights of four dogs are 4, 7, 9, 20 (pounds).
Find the average.
The standard deviation gives us a feel for how the measurements are spread
out on either side of the mean.
When we look at the graph of the data. We can find the mean and the range.

3. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
The directed distance from the mean to each measurement is the deviation of the measurement.
This will always be zero, so it cannot
tell us how the numbers spread out.
To find how the number spread we find the variance.
variance ­ the average of the square of the deviations.
The standard deviation is the square root of the variance.

4. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
1. The measured distances are 12, 7, 15, and 10. Find the mean
and the standard deviation of the distances.

5. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
Normal Distribution (Gaussian distribution) ­ theoretical frequency distribution ­
approximated by data that is collected experimentally.
Shake a box with 10 coins and count the number of heads.
This experiment is completed 1000 times.
Shake a box with 20 coins and count the number of heads.
This experiment is completed 1000 times.

6. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
Shake a box with 1000 coins and count the heads.

7. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013

8. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
2. The mean of a distribution that is approximately normal is 100 and
the standard deviation is 5. Use the standard deviation to tell how
the data are distributed with respect to the mean.

9. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013

10. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
Range:
Median:

11. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013

12. 61. Single­Variable Analysis, Normal Distribution, Box and Whisker Plots.notebook April 08, 2013
3. The measurements are 16, 22, 28, 33, 35, 40, 50, and 120. Use a graphing
calculator to find the mean and the standard deviation and to find minx, Q1,
med, Q3, and max x. Use this data to draw a box and whisker plot.