Week 9 – Jss 1 Third Term Mathematics Lesson Notes

WEEK 9
TOPIC: STATISTICS
MEANING AND USES OF STATISTICS
Statistics is the branch of mathematics which deals with the study of data. It involves

Gathering (collecting data)
Sorting and tabulating data
Presenting data usually means of diagrams
Interpreting results.

USES OF STATISTICS

For record keeping
To forecast or predict future events
For planning purposes
For decision making
To gather information this can be passes from one source to another.
TYPES OF DATA

Qualitative data: this is non- numerical data which can only be described in words. Examples are name, place colour, sex etc.
Quantitative data: A numerical data which is usually given in form of measurement.

FREQUENCY TABLE
EXAMPLE 1: The following figures show the number of children per family in a sample of 40 household. 1, 2, 4, 3, 5, 3, 8, 3, 2, 3, 4, 5, 6, 5, 4, 2, 1, 3, 2, 4, 5, 3, 8, 7, 6, 5, 4, 5, 7, 6, 3, 8, 6, 3, 5, 7, 5, 4, 3.

Use a tally mark to prepare a frequency table for the data
What is the highest frequency of numbers of children per family?

Solution
NUMBER        TALLY        FREQUENCY
1            //            2
2            ////            5
3            //// ////        9
4            //// /            6
5            //// ///        8
6            ////            4
7            ///            3
8            ///            3
                        40
3 is the highest frequency of numbers of children
Example 2: In a further mathematics test the following marks were obtained by a group of students 85, 75, 95, 80, 75, 80, 90, 84, 95, 84, 85, 80, 80, 75, 80, 75, 80, 84, 81, 80, 75, 90, 80.
Use tally mark to prepare a frequency table for this data.
Solution:
NUMBER        TALLY        FREQUENCY
75            ////            5
80            ////            9
81            /            1
84            ///             3
85            //            2
90            ///            3
95            //            2