___________________ techniques include tables, frequency distributions, frequency polygons, measures of central tendency, and measures of variability.

Descriptive.

When using a frequency polygon, scores are recorded on the _______________ axis (abscissa), while frequencies are coded on the _________________ axis (ordinate).

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- Horizontal
- Vertical

_______________ refers to the relative peakedness of a distribution;

- _______________: Distribution is MORE peaked than normal
- _______________: Distribution is LESS peaked than normal
- _______________: Distribution is normal

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- Kurtosis
- Leptokurtic
- Platykurtic
- Mesokurtic

__________________ skewed distribution: Most of the scores are in the negative (low score) side of the distribution.

Positively.

______________________ skewed distribution: Most of the scores are in the positive (high score) side of the distribution.

Negatively.

Note: "The tail that tells the tale."

Measures of Central Tendency:

- ______________: The score or category that occurs most frequently; can have more than one; is susceptible to sampling fluctuations
- ______________: Divides a distribution in half when the data have been ordered from low to high; is insensitive to outliers
- ______________: (M or X-bar) the arithmetic average (M=ΣX/N); least susceptible to sampling fluctuations, but is affected by the magnitude of every score in the distribution

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- Mode
- Median
- Mean

The ________________ is the preferred measure of central tendency when the data is on an ordinal scale; the _________________ is preferred for interval and ratio scales.

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- Median
- Mean

Measure of Central Tendency (from greatest to least) for skewed distributions:

- ________________ skewed: Mean, Median, Mode
- ________________ skewed: Mode, Median, Mean

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- Positively
- Negatively

________________ is calculated by subtracting the lowest score in the distribution from the highest score.

Range.

Variance is calculated using the following formula:

S^{2} (Variance) = __ ____SS __ = __Σ(X-M)__^{2}

N-1 N-1

Where:

- SS = the _________________, which is calculated by subtracting the mean from each score to obtain deviation scores, squaring each deviation score, and then summing the squared deviation scores
- N-1 = the _______________ minus 1 (when calculating sample variance; N when calculating population variance)

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- Sum of Squares
- Number of observations

The ____________________ is more often used as a measure of variability, and is calculated by taking the square root of the variance, which converts it to the same unit of measurement as the original scores:

S = Square Root (SS/N-1)

Standard Deviation.

Identify the Areas Under the Normal Curve:

-1 to +1 SD: ___________%

-2 to +2 SD: __________%

-3 to +3 SD: __________%

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- 68.26%
- 95.44%
- 99.72%

When a constant is added/subtracted to every score in a distribution, the measures of __________________ change, but the measures of _______________ do not. However, when each score is multiplied or divided by a constant, measures of both central tendency and variability are affected.