SaiBook.us Statistics

Example

Title: Standardized scores or z-scores

Grade: 9-a Lesson: S2-L4

Explanation: The best way to understand statistics is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

What is the z-score of a measured value of 0.0034, given µ = 0.0041 and σ = 0.0008?

Step 1a

Identify the 'x',mean 'µ',standard deviation 'σ'.

Explanation:

x = 0.0034,

µ = 0.0041 ,

σ = 0.0008

Step 1b

First subtract 'x' and 'µ'

Explanation:

x - µ = 0.0034 - 0.0041

x - µ = -0.0007

Step 1c

Calculate the Z-score.

Explanation:

Z-score = \$(x - µ) / σ\$

x - µ = -0.0007,

σ = 0.0008

Z-score = \$-0.0007/0.0008\$

z-score of a measured value of 0.0034 = -0.875

Measured value of 0.0034 is less than mean 0.0041 then z-score is negative.