<-- Enter Number Set
<-- Probabilities (or counts for Weighted Average), check box if you are using these →
  

You entered a number set X of {-20,-10,-5,-2,-1,20,40}

From the 7 numbers you entered, we want to calculate the mean, variance, standard deviation, standard error of the mean, skewness, average deviation (mean absolute deviation), median, mode, range, Pearsons Skewness Coefficient of that number set, entropy, mid-range

Ranked Data Calculation

Sort our number set in ascending order

and assign a ranking to each number:

Ranked Data Table

Number Set Value-20-10-5-2-12040
Rank1234567

Step 2: Using original number set, assign the rank value:

Since we have 7 numbers in our original number set, we assign ranks from lowest to highest (1 to 7)
Our original number set in unsorted order was -20,-10,-5,-2,-1,20,40
Our respective ranked data set is 1,2,3,4,5,6,7

Root Mean Square Calculation

Root Mean Square  =  A
  N

where A = x12 + x22 + x32 + x42 + x52 + x62 + x72 and N = 7 number set items

Calculate A

A = -202 + -102 + -52 + -22 + -12 + 202 + 402

A = 400 + 100 + 25 + 4 + 1 + 400 + 1600

A = 2530

Calculate Root Mean Square (RMS):

RMS  =  2530
  7

RMS  =  50.299105359837
  2.6457513110646

RMS = 19.011274850166

Central Tendency Calculation

Central tendency contains:
Mean, median, mode, harmonic mean,
geometric mean, mid-range, weighted-average:

Calculate Mean (Average) denoted as μ

μ  =  Sum of your number Set
  Total Numbers Entered

μ  =  ΣXi
  n

μ  =  -20 + -10 + -5 + -2 + -1 + 20 + 40
  7

μ  =  22
  7

μ = 3.1428571428571

Calculate the Median (Middle Value)
Since our number set contains 7 elements which is an odd number, our median number is determined as follows:
Number Set = (n1,n2,n3,n4,n5,n6,n7)
Median Number = Entry ½(n + 1)
Median Number = Entry ½(8)
Median Number = n4

Therefore, we sort our number set in ascending order and our median is entry 4 of our number set highlighted in red:
(-20,-10,-5,-2,-1,20,40)
Median = -2

Calculate the Mode - Highest Frequency Number

The highest frequency of occurence in our number set is 1 times by the following numbers in green:
(-20,-10,-5,-2,-1,20,40)
Since the maximum frequency of any number is 1, no mode exists.
Mode = N/A

Calculate Harmonic Mean:

Harmonic Mean  =  N
  1/x1 + 1/x2 + 1/x3 + 1/x4 + 1/x5 + 1/x6 + 1/x7

With N = 7 and each xi a member of the number set you entered, we have:
Harmonic Mean  =  7
  1/-20 + 1/-10 + 1/-5 + 1/-2 + 1/-1 + 1/20 + 1/40

Harmonic Mean  =  7
  -0.05 + -0.1 + -0.2 + -0.5 + -1 + 0.05 + 0.025

Harmonic Mean  =  7
  -1.775

Harmonic Mean = -3.943661971831

Calculate Geometric Mean:

Geometric Mean = (x1 * x2 * x3 * x4 * x5 * x6 * x7)1/N
Geometric Mean = (-20 * -10 * -5 * -2 * -1 * 20 * 40)1/7
Geometric Mean = -16000000.14285714285714
Geometric Mean = NAN

Calcualte Mid-Range:

Mid-Range  =  Maximum Value in Number Set + Minimum Value in Number Set
  2

Mid-Range  =  40 + -20
  2

Mid-Range  =  20
  2

Mid-Range = 10

Stem and Leaf Plot

Take the first digit of each value in our number set

Use this as our stem value

Use the remaining digits for our leaf portion

Sort our number set in descending order:

{40,20,-1,-2,-5,-10,-20}
StemLeaf
40
20
-1,2,5,10,20

Basic Stats Calculations

Mean, Variance, Standard Deviation, Median, Mode

Calculate Mean (Average) denoted as μ

μ  =  Sum of your number Set
  Total Numbers Entered

μ  =  ΣXi
  n

μ  =  -20 + -10 + -5 + -2 + -1 + 20 + 40
  7

μ  =  22
  7

μ = 3.1428571428571

Calculate Variance denoted as σ2
Let's evaluate the square difference from the mean of each term (Xi - μ)2:
(X1 - μ)2 = (-20 - 3.1428571428571)2 = -23.1428571428572 = 535.59183673469
(X2 - μ)2 = (-10 - 3.1428571428571)2 = -13.1428571428572 = 172.73469387755
(X3 - μ)2 = (-5 - 3.1428571428571)2 = -8.14285714285712 = 66.30612244898
(X4 - μ)2 = (-2 - 3.1428571428571)2 = -5.14285714285712 = 26.448979591837
(X5 - μ)2 = (-1 - 3.1428571428571)2 = -4.14285714285712 = 17.163265306122
(X6 - μ)2 = (20 - 3.1428571428571)2 = 16.8571428571432 = 284.16326530612
(X7 - μ)2 = (40 - 3.1428571428571)2 = 36.8571428571432 = 1358.4489795918

Adding our 7 sum of squared differences up, we have our variance numerator:
ΣE(Xi - μ)2 = 535.59183673469 + 172.73469387755 + 66.30612244898 + 26.448979591837 + 17.163265306122 + 284.16326530612 + 1358.4489795918
ΣE(Xi - μ)2 = 2460.8571428571

Now that we have the sum of squared differences from the means, calculate variance:
PopulationSample
σ2  =  ΣE(Xi - μ)2
  n

σ2  =  ΣE(Xi - μ)2
  n - 1

σ2  =  2460.8571428571
  7

σ2  =  2460.8571428571
  6

Variance: σp2 = 351.55102040816Variance: σs2 = 410.14285714286
Standard Deviation: σp = √σp2 = √351.55102040816Standard Deviation: σs = √σs2 = √410.14285714286
Standard Deviation: σp = 18.7497Standard Deviation: σs = 20.252

Calculate the Standard Error of the Mean:

PopulationSample
SEM  =  σp
  n

SEM  =  σs
  n

SEM  =  18.7497
  7

SEM  =  20.252
  7

SEM  =  18.7497
  2.6457513110646

SEM  =  20.252
  2.6457513110646

SEM = 7.0867SEM = 7.6545

Calculate Skewness:

Skewness  =  E(Xi - μ)3
  (n - 1)σ3

Let's evaluate the square difference from the mean of each term (Xi - μ)3:
(X1 - μ)3 = (-20 - 3.1428571428571)3 = -23.1428571428573 = -12395.125364431
(X2 - μ)3 = (-10 - 3.1428571428571)3 = -13.1428571428573 = -2270.2274052478
(X3 - μ)3 = (-5 - 3.1428571428571)3 = -8.14285714285713 = -539.92128279883
(X4 - μ)3 = (-2 - 3.1428571428571)3 = -5.14285714285713 = -136.02332361516
(X5 - μ)3 = (-1 - 3.1428571428571)3 = -4.14285714285713 = -71.104956268222
(X6 - μ)3 = (20 - 3.1428571428571)3 = 16.8571428571433 = 4790.1807580175
(X7 - μ)3 = (40 - 3.1428571428571)3 = 36.8571428571433 = 50068.548104956

Adding our 7 sum of cubed differences up, we have our skewness numerator:
ΣE(Xi - μ)3 = -12395.125364431 + -2270.2274052478 + -539.92128279883 + -136.02332361516 + -71.104956268222 + 4790.1807580175 + 50068.548104956
ΣE(Xi - μ)3 = 39446.326530612

Now that we have the sum of cubed differences from the means, calculate skewness:
Skewness  =  E(Xi - μ)3
  (n - 1)σ3

Skewness  =  39446.326530612
  (7 - 1)18.74973

Skewness  =  39446.326530612
  (6)6591.4804738125

Skewness  =  39446.326530612
  39548.882842875

Skewness = 0.9974068467959

Calculate Average Deviation (Mean Absolute Deviation) denoted below:

AD  =  Σ|Xi - μ|
  n

Let's evaluate the absolute value of the difference from the mean of each term |Xi - μ|:
|X1 - μ| = |-20 - 3.1428571428571| = |-23.142857142857| = 23.142857142857
|X2 - μ| = |-10 - 3.1428571428571| = |-13.142857142857| = 13.142857142857
|X3 - μ| = |-5 - 3.1428571428571| = |-8.1428571428571| = 8.1428571428571
|X4 - μ| = |-2 - 3.1428571428571| = |-5.1428571428571| = 5.1428571428571
|X5 - μ| = |-1 - 3.1428571428571| = |-4.1428571428571| = 4.1428571428571
|X6 - μ| = |20 - 3.1428571428571| = |16.857142857143| = 16.857142857143
|X7 - μ| = |40 - 3.1428571428571| = |36.857142857143| = 36.857142857143

Adding our 7 absolute value of differences from the mean, we have our average deviation numerator:
Σ|Xi - μ| = 23.142857142857 + 13.142857142857 + 8.1428571428571 + 5.1428571428571 + 4.1428571428571 + 16.857142857143 + 36.857142857143
Σ|Xi - μ| = 107.42857142857

Now that we have the absolute value of the differences from the means, calculate average deviation (mean absolute deviation):
AD  =  Σ|Xi - μ|
  n

AD  =  107.42857142857
  7

Average Deviation = 15.34694

Calculate the Median (Middle Value)
Since our number set contains 7 elements which is an odd number, our median number is determined as follows:
Number Set = (n1,n2,n3,n4,n5,n6,n7)
Median Number = Entry ½(n + 1)
Median Number = Entry ½(8)
Median Number = n4

Therefore, we sort our number set in ascending order and our median is entry 4 of our number set highlighted in red:
(-20,-10,-5,-2,-1,20,40)
Median = -2

Calculate the Mode - Highest Frequency Number

The highest frequency of occurence in our number set is 1 times by the following numbers in green:
(-20,-10,-5,-2,-1,20,40)
Since the maximum frequency of any number is 1, no mode exists.
Mode = N/A

Calculate the Range

Range = Largest Number in the Number Set - Smallest Number in the Number Set
Range = 40 - -20
Range = 60

Calculate Pearsons Skewness Coefficient 1:

PSC1  =  μ - Mode
  σ

PSC1  =  3(3.1428571428571 - N/A)
  18.7497

Since no mode exists, we do not have a Pearsons Skewness Coefficient 1

Calculate Pearsons Skewness Coefficient 2:

PSC2  =  μ - Median
  σ

PSC1  =  3(3.1428571428571 - -2)
  18.7497

PSC2  =  3 x 5.1428571428571
  18.7497

PSC2  =  15.428571428571
  18.7497

PSC2 = 0.8229

Calculate Entropy:

Entropy = Ln(n)
Entropy = Ln(7)
Entropy = 1.9459101490553

Calculate Mid-Range:

Mid-Range  =  Smallest Number in the Set + Largest Number in the Set
  2

Mid-Range  =  40 + -20
  2

Mid-Range  =  20
  2

Mid-Range = 10

Calculate the Quartile Items

We need to sort our number set from lowest to highest shown below:
{-20,-10,-5,-2,-1,20,40}

Calculate Upper Quartile (UQ) when y = 75%:

V  =  y(n + 1)
  100

V  =  75(7 + 1)
  100

V  =  75(8)
  100

V  =  600
  100

V = 6 ← Rounded down to the nearest integer

Upper quartile (UQ) point = Point # 6 in the dataset which is 20
-20,-10,-5,-2,-1,20,40

Calculate Lower Quartile (LQ) when y = 25%:

V  =  y(n + 1)
  100

V  =  25(7 + 1)
  100

V  =  25(8)
  100

V  =  200
  100

V = 2 ← Rounded up to the nearest integer

Lower quartile (LQ) point = Point # 2 in the dataset which is -10
-20,-10,-5,-2,-1,20,40

Calculate Inter-Quartile Range (IQR):

IQR = UQ - LQ
IQR = 20 - -10
IQR = 30

Calculate Lower Inner Fence (LIF):

Lower Inner Fence (LIF) = LQ - 1.5 x IQR
Lower Inner Fence (LIF) = -10 - 1.5 x 30
Lower Inner Fence (LIF) = -10 - 45
Lower Inner Fence (LIF) = -55

Calculate Upper Inner Fence (UIF):

Upper Inner Fence (UIF) = UQ + 1.5 x IQR
Upper Inner Fence (UIF) = 20 + 1.5 x 30
Upper Inner Fence (UIF) = 20 + 45
Upper Inner Fence (UIF) = 65

Calculate Lower Outer Fence (LOF):

Lower Outer Fence (LOF) = LQ - 3 x IQR
Lower Outer Fence (LOF) = -10 - 3 x 30
Lower Outer Fence (LOF) = -10 - 90
Lower Outer Fence (LOF) = -100

Calculate Upper Outer Fence (UOF):

Upper Outer Fence (UOF) = UQ + 3 x IQR
Upper Outer Fence (UOF) = 20 + 3 x 30
Upper Outer Fence (UOF) = 20 + 90
Upper Outer Fence (UOF) = 110

Calculate Suspect Outliers:

Suspect Outliers are values between the inner and outer fences
We wish to mark all values in our dataset (v) in red below such that -100 < v < -55 and 65 < v < 110
-20,-10,-5,-2,-1,20,40

Calculate Highly Suspect Outliers:

Highly Suspect Outliers are values outside the outer fences
We wish to mark all values in our dataset (v) in red below such that v < -100 or v > 110
-20,-10,-5,-2,-1,20,40

Calculate weighted average

-20,-10,-5,-2,-1,20,40

Weighted-Average Formula:

Multiply each value by each probability amount

We do this by multiplying each Xi x pi to get a weighted score Y

Weighted Average  =  X1p1 + X2p2 + X3p3 + X4p4 + X5p5 + X6p6 + X7p7
  n

Weighted Average  =  -20 x 0.2 + -10 x 0.4 + -5 x 0.6 + -2 x 0.8 + -1 x 0.9 + 20 x + 40 x
  7

Weighted Average  =  -4 + -4 + -3 + -1.6 + -0.9 + 0 + 0
  7

Weighted Average  =  -13.5
  7

Weighted Average = -1.9285714285714

Frequency Distribution Table

Show the freqency distribution table for this number set

-20, -10, -5, -2, -1, 20, 40

Determine the Number of Intervals using Sturges Rule:

We need to choose the smallest integer k such that 2k ≥ n where n = 7

For k = 1, we have 21 = 2

For k = 2, we have 22 = 4

For k = 3, we have 23 = 8 ← Use this since it is greater than our n value of 7

Therefore, we use 3 intervals

Our maximum value in our number set of 40 - -20 = 60

Each interval size is the difference of the maximum and minimum value divided by the number of intervals

Interval Size  =  60
  3

Add 1 to this giving us 20 + 1 = 21

Frequency Distribution Table

Class LimitsClass BoundariesFDCFDRFDCRFD
-20 - 1-20.5 - 1.5555/7 = 71.43%5/7 = 71.43%
1 - 220.5 - 22.515 + 1 = 61/7 = 14.29%6/7 = 85.71%
22 - 4321.5 - 43.515 + 1 + 1 = 71/7 = 14.29%7/7 = 100%
  7 100% 

Successive Ratio Calculation

Go through our 7 numbers

Determine the ratio of each number to the next one

Successive Ratio 1: -20,-10,-5,-2,-1,20,40

-20:-10 → 2

Successive Ratio 2: -20,-10,-5,-2,-1,20,40

-10:-5 → 2

Successive Ratio 3: -20,-10,-5,-2,-1,20,40

-5:-2 → 2.5

Successive Ratio 4: -20,-10,-5,-2,-1,20,40

-2:-1 → 2

Successive Ratio 5: -20,-10,-5,-2,-1,20,40

-1:20 → -0.05

Successive Ratio 6: -20,-10,-5,-2,-1,20,40

20:40 → 0.5

Successive Ratio Answer

Successive Ratio = -20:-10,-10:-5,-5:-2,-2:-1,-1:20,20:40 or 2,2,2.5,2,-0.05,0.5

Final Answers

1,2,3,4,5,6,7
RMS = 19.011274850166
Harmonic Mean = -3.943661971831Geometric Mean = NAN
Mid-Range = 10
Weighted Average = -1.9285714285714
Successive Ratio = Successive Ratio = -20:-10,-10:-5,-5:-2,-2:-1,-1:20,20:40 or 2,2,2.5,2,-0.05,0.5


You have 2 free calculationss remaining




What is the Answer?
1,2,3,4,5,6,7
RMS = 19.011274850166
Harmonic Mean = -3.943661971831Geometric Mean = NAN
Mid-Range = 10
Weighted Average = -1.9285714285714
Successive Ratio = Successive Ratio = -20:-10,-10:-5,-5:-2,-2:-1,-1:20,20:40 or 2,2,2.5,2,-0.05,0.5
How does the Basic Statistics Calculator work?
Free Basic Statistics Calculator - Given a number set, and an optional probability set, this calculates the following statistical items:
Expected Value
Mean = μ
Variance = σ2
Standard Deviation = σ
Standard Error of the Mean
Skewness
Mid-Range
Average Deviation (Mean Absolute Deviation)
Median
Mode
Range
Pearsons Skewness Coefficients
Entropy
Upper Quartile (hinge) (75th Percentile)
Lower Quartile (hinge) (25th Percentile)
InnerQuartile Range
Inner Fences (Lower Inner Fence and Upper Inner Fence)
Outer Fences (Lower Outer Fence and Upper Outer Fence)
Suspect Outliers
Highly Suspect Outliers
Stem and Leaf Plot
Ranked Data Set
Central Tendency Items such as Harmonic Mean and Geometric Mean and Mid-Range
Root Mean Square
Weighted Average (Weighted Mean)
Frequency Distribution
Successive Ratio
This calculator has 2 inputs.

What 8 formulas are used for the Basic Statistics Calculator?

Root Mean Square = √A/√N
Successive Ratio = n1/n0
μ = ΣXi/n
Mode = Highest Frequency Number
Mid-Range = (Maximum Value in Number Set + Minimum Value in Number Set)/2
Quartile: V = y(n + 1)/100
σ2 = ΣE(Xi - μ)2/n


For more math formulas, check out our Formula Dossier

What 20 concepts are covered in the Basic Statistics Calculator?

average deviation
Mean of the absolute values of the distance from the mean for each number in a number set
basic statistics
central tendency
a central or typical value for a probability distribution. Typical measures are the mode, median, mean
entropy
refers to disorder or uncertainty
expected value
predicted value of a variable or event
E(X) = ΣxI · P(x)
frequency distribution
frequency measurement of various outcomes
inner fence
ut-off values for upper and lower outliers in a dataset
mean
A statistical measurement also known as the average
median
the value separating the higher half from the lower half of a data sample,
mode
the number that occurs the most in a number set
outer fence
start with the IQR and multiply this number by 3. We then subtract this number from the first quartile and add it to the third quartile. These two numbers are our outer fences.
outlier
an observation that lies an abnormal distance from other values in a random sample from a population
quartile
1 of 4 equal groups in the distribution of a number set
range
Difference between the largest and smallest values in a number set
rank
the data transformation in which numerical or ordinal values are replaced by their rank when the data are sorted.
sample space
the set of all possible outcomes or results of that experiment.
standard deviation
a measure of the amount of variation or dispersion of a set of values. The square root of variance
stem and leaf plot
a technique used to classify either discrete or continuous variables. A stem and leaf plot is used to organize data as they are collected. A stem and leaf plot looks something like a bar graph. Each number in the data is broken down into a stem and a leaf, thus the name.
variance
How far a set of random numbers are spead out from the mean
weighted average
An average of numbers using probabilities for each event as a weighting
Example calculations for the Basic Statistics Calculator

Basic Statistics Calculator Video


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