The Observational Statistics calculator computes the most common observational statistics for columns in a table of data. 

INSTRUCTIONS: Enter the following:

• (x) Numeric Observations.  Enter rows of comma separated numeric values e.g. 4,-1.2,8,9 . To do so, click on the field and
  1. enter the data manual, or 
  2. use cut / copy / paste, or
  3. upload a csv with a uniform table of real numbers.
• (c) Column Number.  

STATISTICS: The calculator returns the descriptive statistics below for the identified column.  

• count - number (n) of values in the column.
• min - minimum value
• max - maximum value
• sum(Σx)  - sum of the values in a set.
• Σx² - sum of the squared values
• (Σx)² - square of the summed values.
• mean - mean (average) of values
• median - middle ordered value
• mid point - mid point of value range
• mode - most frequent observation
• range - difference between the max and the min.
• MAD -  Mean Absolute Deviation
• SDOM - Standard Deviation of Mean
• sort up - values in ascending order.
• sort down - values in descending order.
• var-pop - population variance of the values
• sd-pop - population standard deviation of the values
• var-sample - sample variance of the values
• sd-sample - sample standard deviation of the values

How to Enter Data

Enter the data in comma separated values with a new line for each record.  Note: it is important to be consistent with number of columns when manually entering the data.

One can also upload a CSV (comma separated values) file from your device into this calculator by clicking on the

. button. 

Example

Enter the following tabular data and choose a  column between 1 and 4:

-56,347,356,147
326,-116,386,-276
23,309,-230,-109
390,49,385,405
-87,289,32,33
-210,382,244,5
-85,206,386,44
318,-294,-16,-294
357,-152,-154,147
482,-16,-241,-191
-85,281,267,280
254,364,352,72
-32,-322,-90,-385
460,434,-89,461
23,49,-243,-42
128,-228,-137,-61
370,-75,32,-287
306,-387,51,33
-23,-282,467,271

You will see the observational statistics for that column.

This calculator is a prominent feature with other statistical functions in the College Level Statistics Calculator (Stat Calc).

Statistics Calculators

• Observational Stats:  This function accepts a table (rows and columns separated by commas) of numbers and calculates observational statistics for any of the columns.  This includes count, min, max, sum, sum of squares (Σx²), square of the sum (Σx)², mean, median, mode, range, mid point, rand, sort up, sort down, rand, population variance, population standard deviation, the sample/experimental variance, sample/experimental standard deviation.
• Simple Stats: This is also provides a full set of observational stats, but on a single row of numbers separated by commas. The observational stats include count, min, max, sum, sum of squares (Σx²), square of the sum (Σx)², mean, median, mode, range, mid point, rand, sort up, sort down, rand, population variance, population standard deviation, the sample/experimental variance, sample/experimental standard deviation.
• Frequency Distribution:  This function lets you enter a string of numbers separated by commas, a low and high range and a number of bins.  It then computes how many of the observations are in each of the bins between the high and low values designated. 
• Paired Sample t-test:  This computes the various parameters associated with the Paired Sample t-test.
• ANOVA (one way): The computes the F Score and details for one way analysis of variance for a nxm matrix of observations.
• (χ²) Chi-Square Test: This computes the Chi-Square value for an nxm array of data and provides the degrees of freedom.
• Linear Regression:  This computes the regression line (least-squares) through a set of X and Y observations.  It also computes the regression coefficient (r).
• Least-squares Trend Inference :  This is a linear equation used with Linear Regression to compute a predicted value of Y based on X.
• Wilcoxon Signed Rank Test: This provides the Wilcoxon statistics and critical value for two groups of numeric observations based on an alpha value and whether it's a one or two tailed test.
• Slope-Intercept form of a Line: This provides the slope intercept form (y = mx+b) of a line based on two coordinates.
• Slope between two points: This provides the slope between two coordinates.
• Linear Equation: This computes the range (y) of a linear equation (y = mx +b) and includes a graphing function.
• Probability between z SCORES: This computes the area under the Normal Distribution curve between two z SCOREs which equates to the probability of an event in that range.
• Stats Calc: College level statistics calculator with a bundle including most of the functions in this list.
• Count: This computes the number (n) of observations in a set of numbers.
• Minimum: This computes the minimum (min) value in a set of numbers.
• Maximum: This computes the maximum (max) value in a set of numbers.
• Numeric Sort: This sorts (ascending or descending) a set of comma separated numerical observations.
• Random Sample (k items): The provides a random subset of a specified size (k) in a set of comma separated numerical observations.
• Random Real Number in Range: The provides a random real number between two specified real numbers (upper and lower bounds).
• Radom Integer: The provides a random integer between two specified integers (upper and lower bounds).
• Frequency Distribution: This provides a frequency distribution table for a comma separated set of numbers with a specified number of frequency bins between a lower and upper data range. 
• Sum (Σx): This is computes the sum of the values in a set.
• Sum of Squares (Σx²): This computes the sum of the squared values in a set.
• Sum Squared (Σx)²:  This computes the square of the summed values in a set.
• Mean (μ): This computes is the mean (average) of values in a set.
• Median: This identifies the middle ordered value in a set of numbers.
• Statistical Mode: This identifies the most recurring observation in a set of numbers.
• Mid Point: This is identifies the mid point of the observation range in a set of numbers.
• Range: This is computes the difference between the max and the min values in a set of number.
• Population Variance (σ²): This computes the variance, a metric regarding the spread of values, for a population set of numeric values.
• Population Standard Deviation (σ):  This computes the standard deviation for a population set of numeric values.
• Sample Variance (s²) : This computes the variance, a metric regarding the spread of values, for a sample set of numeric values within a greater population.
• Sample Standard Deviation (s): This computes the standard deviation for a sample set of numeric values within a greater population.
• z SCORE Formula: This computes the z SCORE for a value base on the mean and standard deviation.
• z SCORE: This computes the z SCORE for a value (Raw Score) based on a set of values, and whether that set is sample or population. 
• Percentile: This computes the percentile of a value (y) in a set (X) of values.
• Standard Deviation of Mean (SDOM):  This computes the standard deviation of mean, sometimes also known as the standard error of the mean (SEM), useful to helps quantify the uncertainty in the estimate of the mean.  
• Percent Relative Standard Deviation (%RSD): This computes the percent relative standard deviation, also known as the coefficient of variation (CV).  The %RSD is a measure of the dispersion of a probability distribution.

Thanks to Dr. Lee Hammerstrom, professor of math stats at Eastern Nazarene College, for his advice and testing.

The Math

The formulas for the statistics are as follows:

sum

     `S = sum(x)`

sum of squares

      Σx²`= sum(x^2)`

square of the sum

     (Σx)² = `(sum(x))^2`

averages

• mean:     `mu = (sum(x))/n`  where n is the number of observations
• median:  middle value if in an odd number of observations.  If there is an even number of observations, it's the average of the two middle values.
• mid-point:  `mp = (min + max)/2`

variance

• Population Variance: `sigma^2 = (sum_1^n(x_n-mu)^2)/n`
• Sample Variance: `sigma^2 = (sum_1^n(x_n-mu)^2)/(n-1)`

standard deviation

• Population Standard Deviation:   `sigma = sqrt((sum_1^n(x_n-mu)^2)/n)`
• Sample Standard Deviation:   `sigma = sqrt((sum_1^n(x_n-mu)^2)/(n-1))`

Mean Absolute Deviation

• MAD = `1/n sum_(i=1)^n | x_i - barx |`

Statistics Calculators

• Stats Calc - Complete set of entry level college statistics functions
• Simple Stats - Complete set of Observational statistics for a set of data
• Linear Regression - Least-squares trend line for a set of data
• One Way ANOVA - One way Analysis of Variance for three sets of data

Growth Calculators

• Logistic Growth
• Malthusian Growth Model
• Organism Count (Logistic Growth)
• Max Potential Growth Rate (biotic potential)
• How Many Ancestors
• Simple Stats Calc - Simple observation statistics (see below)
• Math Statistics Calc - College level statistics and regression calculator.

Statistics in Culture

"There are three kinds of lies: lies, damn lies and statistics."   Mark Twain