Chapter 2F Flashcards
(5 cards)
Is standard deviation and variance the same as measure of spread?
Are they the same as measures of spread?
Yes. Variance and standard deviation are both measures of spread, also called measures of dispersion or measures of variation. They show how much the data varies around the average (mean). They are not measures of central tendency (which are mean, median, and mode).
Key Symbols and Definitions: In Statistics Chapter 2
Key Symbols and Definitions:
* σ² = variance for a population
* s² = variance for a sample
* σ = standard deviation for a population
* s = standard deviation for a sample
* x = individual data value
* μ = population mean
* x̄ = sample mean
* N = number in population
* n = number in sample
Definition of Variance (Flashcard-ready):
Definition of Variance (Flashcard-ready):
Variance is the average of the squared differences from the mean. It measures how spread out the values in the data set are. A large variance means the data is widely spread; a small variance means it is closely packed.
Where do variance and standard deviation fit in statistics?
Where do variance and standard deviation fit in statistics?
They are used when we want to understand how reliable, consistent, or scattered our data is. They are important in many areas of statistics, especially in comparing different data sets or testing whether a result is likely to happen again.
Definition of Standard Deviation (Flashcard-ready):
Definition of Standard Deviation (Flashcard-ready):
Standard deviation is the square root of the variance. It shows how far, on average, the data values are from the mean. It is in the same unit as the original data and is often used because it’s easier to understand than variance.
