## Wednesday, May 5, 2010

### STATISTICS (ANALYSIS) : mean, mode & median

The Next Phase in Statistics is Data Analysis. In this segment we will be focusing on the following:
.1 Averages
.2 Histogram
.3 Other forms of presentation (Dot Diagram, Stem and Leaf)

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.1 Averages
'Before you can begin to understand statistics, there are four terms you will need to fully understand. The first term 'average' is something we have been familiar with from a
very early age when we start analyzing our marks on report cards. We add together all of our test results and then divide it by the sum of the total number of marks there are. We often call it the average. However, statistically it's the Mean!' [source: http://math.about.com]

1. Define the following statistical terms: Mean, Mode and Median
3. Provide an example on each of the terms
4. When do we use mean, mode or median?
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.2 Frequency Table and Histogram

Identify the characteristics of a Histogram.
What is/are the primary difference/s between Histogram and Bar Chart?

Do a simple survey in class and complete the following tasks
Complete a Frequency Table
• Use Numbers and Plot a Histogram (label the axes and provide a suitable Title)
• Find the (a) mean, (b) mode and (c) median
• Which of the above averages ie. mean, mode or median you think best represents your findings about your survey? Why?

Group 1: Birth months of all your classmates
Group 2: Home location of all your classmates (North, South, East, West)
Group 3: Number of siblings of individual student
Group 4: Types of CCA
Group 5: Favourite genre of movies: Horror, Comedy, Thriller, etc etc

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Other types of Representation

1. 1) The definition of...
"mean" is the average when one adds up all values and divides it from the number of values.
"mode" is the value that appears the most number of times or the most common value.
"median" is the middle value of the number of values.

3) An example for the 3 terms...
The "mean" mark of the whole cohort of the students who sat for the math test is 35.
The "mode" of the the number of hours students use the internet per day is 4 hours.
The median of the 3 boys height is 156cm.

4) We use each of the 3 terms when...
Finding the average of the test marks or average weight of students.
Finding the most number of students who use the internet for a specific period of time.
Finding the student with height median to the students in class.

~Jia Le

2. Median: The anything that is standing is the middle of three or more objects. It is the midpoint of a frequency distribution of observed values or quantities. Whenever there is a even number, to find the Median, you take the 2 items or objects that is in the middle. You add the Length, height, weight etc. And divide by 2 to get the Median

Mean: It is the average number or objects in a group of them. Just add up all the numbers, then divide by how many numbers there are to find the Mean

Mode: The value that occurs most frequently in a given set of data. For example there are 3 chickens, 2 ducks and 1 Penguin. The mode would be the Chicken as it has the most.

3. For median please remember to arrange the items/objects in ascending or descending order first