choose correct answer

A-Which of the following is NOT one of the methods that perform effective dimensionality reduction?

		1-Decision-tree
		2-PCA
		3-Discretization
		4-Attribute reduction

B-Data dispersion, also known as variance analysis, is the degree to which numeric data tend to spread and can be characterized by such statistical measures as ________, ________, and the ________.

		1-mean deviation, measures of skewness, and the coefficient of variation.
		2-mean deviation, five-number summary, and the coefficient of variation.
		3-median deviation, variance analysis, and the efficient of variation.
		4-null deviation, measures of skew, and the efficient of variation.

C-What are the three classes of data visualization techniques?

		1-Geometric, hierarchical, and icon-based
		2-Landscapes, hierarchical, and parallel coordinates
		3-Geometric techniques, tile bars, and tree maps
		4-Icon-based, Chernoff face, and stick figures

D-The key points of ranking cube are:

		1-Partition data on both selection and ranking dimensions
		2-Compute measures for each group/block
		3-Simultaneously push selection and ranking conditions to locate the block with top score.
		4-All of the above