STATISTICS Flashcards
Basically the average and represented by the symbol x bar
MEAN
How to calculate the Mean?
Take the sum of the set of numbers divided by to the numbers that are in the data set
Basically the middle number or simply the middle number of data set?
MEDIAN
How to find Median?
Eliminate the first and the last number then the next numbers until left with the middle number
What to do if you come accross a situation where you dont have one number in the middle (example 2 numbers)?
Take the average of those two middle numbers. Add them up then divide by 2.
Simply the most frequent number in the data set?
MODE
A data set with two modes is called what?
Binomial data set
What do you call a data set with only one mode?
Unimodal
The difference between the highest number and the lowest number
RANGE
What is the first step to find the mean, median, mode, and range?
Arrange the numbers in increasing orders
A statistical term that describes a division of observations into four defined intervals based on the values of the data and how they compare to the entire set of observations.
Quartile
The difference between the upper and lower quartile values in a set of data. (Q3 - Q1)
Interquartile range
It is commonly referred to as IQR and is used as a measure of spread and variability in a data set.
Interquartile range
Median of the lower half of the data set
1st Quartile (Q1)
Basically the median of the entire data set
2nd Quartile (Q2)
Median of the upper half of the data set
3rd Quartile (Q3)
A single data point that goes far outside the average value of a group of statistics
Outlier
Also known as box plot. Summarizing a set of data.
Box and Whisker Plot
Shows how the data is distributed and it also shows any outliers.
Box and Whisker Plot
Useful way to compare different sets of dara as you can draw more than one boxplot per graph.
Box and Whisker Plot
Measurement of the distortion of symmetrical distribution or asymmetry in a data set. Demonstrate bell curve.
Skewness
If you have a data that is perfectly symmetrical, the mean is gonna be _______ to the median
Equal
The box and whisker plot is evenly distributed
Represents a symmetric distribution
If the tail of the graph is in the right side. Sample mean will be in the right. Mean will be greater than the median. Some referred as a Positive Skew.
Skewed to the right
The box and whisker plot : right side of the box is longer than the left side. Even if the box is equal, the right side line longer than the left side. Q3 - Q2 > Q2 - Q1
Skewed to the right
If the tail of the graph is in the left side. Sample mean will be in the left of the median. Mean is less than the median. Also known as Negative Skew.
Skewed to the left
Q2 will be closer to Q3 in the box plot. Left side line is longer than the right side. Q2 - Q1 > Q3 - Q2
Skewed to the left
The Mode in this is the number with the most dots. Visually groups the number of data points in a data set based on the value of each point.
Dot Plot
Gives a visual depiction of the distribution of the data, similar to a histogram or probability distribution function.
Dot Plot
A type of plot with 2 columns ( left=stem, right=leaf) and may have decimal values. Technique used to classify either discrete or continuous variables.
Stem and Leaf Plot
2 columns where the left is a value with an accompanying frequency on the right. A “t-chart” or two-column table which outlines the various possible outcomes and the associated frequencies observed in a sample.
Frequency table
Similar to bar graph yet bars are interconnecting. The height of a rectangle (the vertical axis) represents the distribution frequency of a variable (the amount, or how often that variable appears).
Histogram
frequency divided by n
Relative frequency
