Statistics: the gathering, organization, analysis, and presentation of numerical information
Raw data: the unprocessed information collected for a study
Variable: the quantity being measured
1) continuous variable: any value within a given range
2) discrete variable: certain separate values (often integers)
Frequency tables/diagrams: shows an overview of the distrubution of values of the variables and reveal trends in the data
Bar graph: a chart or diagram that represents quantities with horizontal or vertical bars whose lengths are proportional to the quantities. (eg. hair colour, citizenship)
Histogram: a special form of bar graph in which the areas of the bars are proportional to the frequencies of the values of the variable.
- the bars in a histogram are connected ( continuous range of values )
- histograms are used for variables whose values can be arranged in numerical order, especially continuous variables (eg. time, weight, temperature)
Frequency Polygon: similar to a histogram or bar graph. But the only difference is that frequencies versus variable values have to be plotted and then join the points with straight lines.
Example 1: Frequency table
Sum Tally Frequency
2 4 4
3 2 2
4 3 3
5 9 9
6 8 8
7 5 5
8 6 6
9 5 5
10 4 4
11 3 3
12 1 1
intervals: a set of all numbers between two given numbers.
Range: the difference between the highest and lowest values in a set of data.
Relative-frequency table/diagram: the frequency of a data group as a fraction or percent of the whole data set.
Example 2: Relative-frequency table
Score Midpoint Tally Frequency Relative Frequency
34.5-39.5 37 1 1 0.033
39.5-44.5 42 1 1 0.033
44.5-49.5 47 0 0 0
49.5-54.5 52 1 1 0.033
54.5-59.5 57 2 2 0.067
59.5-64.5 62 4 4 0.133
64.5-69.5 67 4 4 0.133
69.5-74.5 72 6 6 0.200
74.5-79.5 77 4 4 0.133
79.5-84.5 82 3 3 0.100
84.5-89.5 87 2 2 0.067
89.5-94.5 92 1 1 0.033
94.5-99.5 97 1 1 0.033
Categorial data: data that can be sorted or divided by type rather than by numerical values.
Circle graph (or pie charts): a graph that represents quantities with segments of a circle that are proportional to the quantities.
Pictographs: a chart or diagram that represents quantities with symbols.
Comments:
Maher and Kimberly: we really like your tutorial and it helped us understand it! good job and keep up the good work.
Comment:
By: Osman Osman
Your page is full of information … Well done
But you could have included some pictures and graph to demonstate and support your examples.
Peace *__*
by: daniella
i agree with osman, since it is data analysis with graphs, perhaps graphs should have been inculded. But still a decent job was done
