Spring 2026--March 16th Jerry's Notes for statistics

Textbook 3.1

EXP 3.1.2

 1-1. Transpose

1-2. Arrange A to Z

EXP 3.1.4

Mean= Average

Textbook 3.2 

Range = highest value - (Subtraction=Minus, less) lowest value

Deviations: The amount by which a measurement is different from a fixed number or amount (Meaning from Cambridge)

More calculator information: https://www.calculatorsoup.com/calculators/math/basic.php 

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x̄ (X bar) https://wumbo.net/symbols/x-bar/

Learn "X bar" definition and some example website:

https://www.geeksforgeeks.org/maths/what-is-x-bar-in-statistics/

I share something about X bar information website with you~

Definition of x̄

x̄ is a measure of central tendency that represents the average value of given sample data points with a single value. x̄ is also known as a sample mean. Mathematically, it is defined as the sum of all given data points divided by the total number of data points. The formula for calculating x̄ or sample mean is given below:

x̄ = ( x1 + x2 + x3 +..........+ xn)/n

How to Calculate x̄

For a given sample of data

To calculate the sample mean x̄. Follow the steps given below:

Step 1: Sum all the data points given in the sample.

Step 2: Divide the sum by the total number of data points.

Example: For given a sample data set {4, 8, 6, 5, 3, 7}, Find x̄.

Solution:

x̄ = (4 + 8 + 6 + 5 + 3 + 7)/6

x̄ = 33/6

x̄ = 5.5 

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Textbook Practice

How to become "8.02"? 

Solution 1

Assignment

From Table : Sum of Deviations of Weights of Cats to 

Table : Squared Deviations of Weights of Cats