Unit 5

grouped frequency table

A frequency table is a table that shows the total for each category or group of data. View our Unit on Data and Graphs. More Math Help: Grants. Online Degrees.

sample

A selection taken from a larger group (the "population") so that you can examine it to find out something about the larger group. Example: you ask 100 randomly chosen people at a football match what their main job is. Your sample is the 100, and the population is all the people at that match.

sample random sampling

A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen. An example of a simple random sample would be the names of 25 employees being chosen out of a hat from a company of 250 employees.

measures of center

Image result for measures of center math definition A measure of central tendency (measure of center) is a value that attempts to describe a set of data by identifying the central position of the data set (as representative of a "typical" value in the set). We are familiar with measures of central tendency called the mean, median and mode

mutually exclusive

In logic and probability theory, two propositions (or events) are mutually exclusive or disjoint if they cannot both be true (occur). A clear example is the set of outcomes of a single coin toss, which can result in either heads or tails, but not both.

maximum value

Mathematics. Also called relative maximum, local maximum. the value of a function at a certain point in its domain, which is greater than or equal to the values at all other points in the immediate vicinity of the point. Compare absolute maximum. the point in the domain at which a maximum occurs.

measures of spread

Measures of spread describe how similar or varied the set of observed values are for a particular variable (data item). Measures of spread include the range, quartiles and the interquartile range, variance and standard deviation.Jul 4, 2013

stem and leaf plot

Stem and Leaf Plots show the Spread & Shape of Data. To Use the QI Macros Stem and Leaf Plot Maker: Click on the QI Macros Menu, then Chart Templates and then Stem and Leaf Plot.

range

The difference between the lowest and highest values. In {4, 6, 9, 3, 7} the lowest value is 3, and the highest is 9, so the range is 9 − 3 = 6. Range can also mean all the output values of a function. See: Range of a function. The Range (Statistics)

Frequency

The frequency of a particular data value is the number of times the data value occurs. For example, if four students have a score of 80 in mathematics, and then the score of 80 is said to have a frequency of 4. The frequency of a data value is often represented by f.

inter-quartile range

The interquartile range (IQR) is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.

mean

The mean is the average of the numbers: a calculated "central" value of a set of numbers. To calculate: Just add up all the numbers, then divide by how many numbers there are.

minimum value

The minimum value of a function is the place where the graph has a vertex at its lowest point. In the real world, you can use the minimum value of a quadratic function to determine minimum cost or area.

mode

The number which appears most often in a set of numbers. Example: in {6, 3, 9, 6, 6, 5, 9, 3} the Mode is 6 (it occurs most often). See: Median.

median

To find the Median, place the numbers you are given in value order and find the middle number. Example: find the Median of {13, 23, 11, 16, 15, 10, 26}. Put them in order: {10, 11, 13, 15, 16, 23, 26} The middle number is 15, so the median is 15. (If there are two middle numbers, you average them.)

histogram

graphical display where the data is grouped into ranges (such as "40 to 49", "50 to 59", etc), and then plotted as bars. Similar to a Bar Graph, but in a Histogram each bar is for a range of data

outlier

outlier. A data point that is distinctly separate from the rest of the data. One definition of outlier is any data point more than 1.5 interquartile ranges (IQRs) below the first quartile or above the third quartile.