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Unit 4 - Inferences About Populations

Terms in this set (36)

One or more parts of the population are favored over others in an examination of gathering information.

You have two sets of related data you want to compare. (EX: ice cream sales and outside temperature)

Box and Whisker

A diagram that uses a number line to show the distribution of a data set. The diagram uses a summary of data; Minimum, Q1( lower quartile , Q2(median), Q3 (upper quartile), and Maximum.

Information, usually numerical, organized for analysis.

Any pictorial device, such as a scatter plot or bar graph, used to display categorical or numerical data.

The number of times an item, number, or event occurs in a set of data.

A way of displaying numerical data using horizontal or vertical bars so that the height or length of the bars indicate s frequency into organized.

The act or process of deriving logical conclusions from premises known or assumed to be true.

Inter-Quartile Range (IQR)

The difference between the first (Upper) and third (lower) quartiles.

Lower Quartile (LQ or Q1)

The median of the lower half of the data set.

The largest value in the data set.

Mean Absolute Deviation (MAD)

Is the average distance between each data value and the mean.
TOTAL DISTANCE FROM THE MEAN FOR ALL VALUES
MAD = number of data values

The sum of the data values divided by the number of items in the data set. Also known as "fair share".

Measures of Center

Number that describe the set of data (mean, median, mode).

Measures of Spread

The range and MAD are both common ways to measure the spread for a data set.

The middle number of the data ordered from largest to smallest. If there is an even number in the data, the median is the mean of those two middle numbers. (NOTE: This is a good choice to represent the center of distribution if the data is skewed or outliers are present.

The smallest value in a set of data.

The number(s) that occur most often in a data set. There can be more than one mode.

Data that are more than 1.5 times the inter-quartile range less than Q1 or greater than Q3.

Qualitative/ Categorical Data

Information that are specific labels or names for categories.

Divide an ordered set of data into four equal groups.

Quantitative/ Numerical Data

Data that can be counted or measured.

A large group from which a smaller group is chosen to represent.

The difference between the largest and smallest numbers in the data set. A measure of spread for data.

Random Sampling

A sample where each item or person in the population is as likely to be chosen as any other.

Representative Sampling

A smaller group chosen from a larger group for gathering information.

A part of the population that we actually examine in order to gather information.

Scatter Plot (Data Plot)

A coordinate graph showing the relationship, if any between two variables.

When the data has a "long tail" on one side or the other.

The collection and analysis of data.

Stem and Leaf Plot

A graphical method used to represent ordered numerical data. Typically,the stem is about the first digit of each data value and the leaf is about the last digit.

Upper or lower values where the range for outliers begin.

Unbiased Sample

A selection that is representative of the entire population in an examination of gathering information.

Univariate Data

One set of data to be based for comparison (mean, median, mode, range, quartiles).

Upper Quartile (UQ or Q3)

The median of the upper half of the set of data.

Variation/ Variability

A set of numerical data indicates how widely spread or closely clustered the data values are.

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