Measures of Center
What are the best measures of center to use for Stats?
Mean and Median
What does range measure?
Max - Min
What does the first "S" stand for in SOCS and what would you include with it?
Shape - strong/weak, positive/negative, linear/non linear
What summary statistics are resistant to outliers?
Center = Median, Spread = IQR
When will standard deviation be zero?
Standard deviation will be zero if all the data in the set are the same value.
What measure of center is the middle?
MEDIAN measures the middle
What is IQR?
Q3 - Q1
What does "O" stand for in SOCS and what would you include with it?
ODD - Gaps, Outliers, Skew
What summary statistics are not resistant to outliers?
Center = Mean
Spread = Range, Standard Deviation, Variance
How do you know what type of skew there is?
The tail side of the skew is what type of skew it is.
Tail on left side = Left skew
What measure of center is the most?
MODE measures the most frequent value in the data set
What is “sigma” the symbol of?
Standard deviation
What does "C" stand for in SOCS and what would you include with it?
CENTER - Mean, Median, Mode (not the best choice)
How do you find lower outliers?
Lower Bound = Q1 - 1.5(IQR)
What is the formula for Z score?
X - Mean/Standard Deviation
What measure of center is the average?
MEAN measures the average
What is the difference between standard deviation and variance?
Variance is standard deviation squared.
What does "S" stand for in SOCS and what would you include?
SPREAD - IQR, Range, Standard Deviation, Variance ( not the best choice)
How do you find upper outliers?
Upper bound = Q3 + 1.5(IQR)
What does a Mosaic Plot do that a Segmented Bar Graph doesn't?
A Mosaic Plot scales the x-axis to help show sample size.
Why is median resistant to outliers?
The median of the data set wont be affected by outliers because its just the middle of the data set and doesn't average in extremes like mean does.
What is the sentence stem to describe Standard Deviation?
On average the values of (context) vary (standard deviation) from the (mean)
How many things do you need to write for each part of SOCS?
Shape - direction/strength/linear
Odd - All odd features of the data
Center - Just pick one
Spread - Just pick one
How would you use the calculator to find outliers?
2nd -> y= -> plot boxplot
What do the numbers .68-.95-.997 mean?
Empirical Rule
.68 = area under curve covered by 1st SD
.95 = area under the curve covered by 2nd SD
.997 = area under the curve covered by 3rd SD