**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