Statistics (Week 3b)

Deviation score = X - μ

Deviation score formula?

Variance = 𝛴(X - μ)^2 / N

Formula for Variance?

√Variance

Formula for standard deviation

Variability

Provides a quantitative measure of the differences between scores in a distribution and describes the degree to which the scores are spread out or clustered together

X = μ + Zσ

Raw score formula?

range

The distance covered by the scores in a distribution, from smallest score to the largest score

z-score

The numerical value of the __ specifies the distance from the mean by counting the number of standard deviations between X and μ

z-scores, standard scores

The purpose of __ or __ __, is to identify and describe the exact location of each score in a distribution

positive, negative

The sign of the z-score (+ or −) signifies whether the score is above the mean (__) or below the mean (__).

raw scores

These original, unchanged scores that are the direct result of measurement are called __ __.

Standard deviation

__ uses the mean of the distribution as a reference point and measures variability by considering the distance between each score and the mean.

Variability describes the distribution, Variability measures how well an individual score (or group of scores) represents the entire distribution.

a good measure of variability serves two purposes:

Range = Xmax - Xmin

formula for range?

Standard deviation

is the square root of the variance and provides a measure of the standard, or average distance from the mean.

Variance

the mean of the squared deviations, the average squared distance from the mean.

z = (X - μ) / σ

z-score formula?