Box & Whiskers
Box and whisker plots are used to display what?
The 5 # summary
How many quartiles are in a 5 # summary?
Four
A bar graph that touches with numerical data organized into equal intervals is what?
Histogram
Mode is a measure of what and how do you recognize it?
A measure of center for the MOST repeating number in a data set
The most frequently used statistical display in statistics is...
The normal curve - bell curve
The minimum is the...
lowest # in the data set
Each quartile is worth what % of the data?
25%
What type of table do you need to build a histogram?
A frequency table
Variance measures spread from each data point back to the what AND leads to what distribution measurement?
Back to the mean
leads to standard deviation
What three characteristics must be present in a histogram to make the generalization of a normal curve?
1. symmetric
2. Unimodal
3. All measures of center are equal
Quartile 1 is the...
Median of the lower 50%
How do you find the IQR?
Q3 minus Q1
What is an interval?
The bars and the # range for each on the histogram and on a frequency table
MAD, IQR and Standard Deviation all measure what?
Spread
What % of data lives under the curve?
100%
The middle data point in the set is the...
Median
What percent of the data is the IQR looking at?
The middle 50%
How many intervals are recommended on the frequency table to draw a histogram with good shape?
4 - 12 intervals
The sum of all data points divided by the number of data points is what measure of center?
The mean (average)
What % of the data is represented for more than +2 standard deviations away from the mean?
2.28% of the data
The Median of the upper 50% of the data is ...
Quartile 3
How do you measure the shape of a box and whisker?
Compare the minimum and maximum (ends of the whiskers) back to the median line in the box.
If a histogram stair steps down to the left what is its shape?
Skewed left
If you are looking at a statistical display like a box and whisker or histogram and you say words like skewed left, skewed right, normal what are you describing?
The shape
If the mean increases or decreases on the x axis what happens to the curve?
If the standard deviation increases or decreases what happens to the curve?
Changes locations by sliding left or right on the # line.
Increase more spread flatter curve
Decrease less spread (more clustered to mean) steeper curve