## Saturday, May 14, 2011

### Sec 1 Maths Performance Task Reflections

Statistical Journal

(I) Role of Statistics in Real Life

Statistics is a collection of key data . It can be a display of a recorded set of numbers which the key information to show result , tends over a period of time or . Statistics is to organization of data. Statistics may be presented in different forms of graphs or charts. Statistics tells us facts that we do not notice.

Example :
Examples of graphs and charts include Line graph , Pie-charts , Bar graphs , Dot diagram , Stem and Leaf , Pictogram and Histogram.
 Bar Graph

Fact sheet by Singapore Tourism Board

Source : https://app.stb.gov.sg/asp/new/new03a.asp?id=12283

 Line Graph

Fact sheet

by Singapore Tourism Board

Source :
https://app.stb.gov.sg/asp/new/new03a.asp?id=12283

Using the graphs and charts , we can interpret graphs and draw inferences from what we analyze from the graphs and charts .
Eg : From the graph we can see that most of the people boarding this bus in the morning peak hours are mostly students so we can infer that the bus is to stop at a bus stop where there is a school in the vicinity .

We can also compare the data in the graphs and charts to have conclusions on the set of data represented by the graphs or charts .
Eg : The number of mobile phone subscribers in 2000 - 600000
The number of mobile phone subscribers in 2004 - 1000000
We can conclude that the number of mobile phone subscribers are increasing at the rate of 100000 each year as the years goes by.

After collecting data , we have to use tables like frequency table to organize data. Frequency is the quantity of the class of the table. By using strokes , we can calculate the quantity of the class of the table which is the tally .

Other then the presentation of statistics , we can also utilize the measures of central tendencies like mean , median and mode. They belongs to the group called Average. The most common type of " averages" used in interpreting graphs is mean . This is a number which " eves out" or balances a set of data . We can find the mean by adding up all the values in the set of data and dividing it on the quantity of the values . Next is the median , it is the " middle mark" when the marks are listed in a ascending order. To find the position of the median in the set of data , we can take the quantity of the values in the data and divide it by two if the quantity is a even number or add 1 to the quantity before dividing it by two. Find the value which is in the position ( we had found earlier ) .

Eg : Set of data arranging in ascending order.      1 2 3 4 5 6 7 8 9 10 11
Find the position = (11+1) /2
= 6
Number 6 is in the 6th position so it is the median in this set of data . Median is useful when one wants to find out if one is on the better half of the population.

Lastly it is the mode. The mode is the number that appears the most frequent in a set of data. To find mode ,we can arrange the data in ascending order and find the number that appears for the most number of times. Finding the mode is most useful when you want to establish the latest fashion , fads and trends .

Eg : Data( arranged in ascending order)  1 2 3 3 3 4 5 6 6 7 7 7 7 7 7 7 7 8 9 9 9 10

Number 7 appears for the most number of times in the data. 7 is the mode for this set of data.

Eg : When you see most of the people drinking bubble tea , you would know that is the latest fashion - popular ( mode) .

Source : ACE Learning portal ( Mavis) http://www.ace-learning.com.sg/sys/home/index.php?sd=4121993f7a0ce008ccaac9fbd28a80992226b0&r=683028343
Information are from the above website but the examples are from Mavis .

Statistics are used in surveys , commercial advertisements to show results in their products , Science questions to present the speed of a object . We can record information and keep track of people in tables in the form of a name list . We can find useful tables in calendars , it might not look like the usual tables that we learnt in school, the days of the week are the labels and the dates are the frequency .

In newspaper articles , statistics are collected to present interesting facts and figures of national events , particular important events in the national or international and accompany reports. It might not be presented in a graph but in figures.

Eg :

1. Number of days from Opening to Closing Ceremony = 16 days [exact]

2. Cost of Opening Ceremony Ticket = 5000 yuan [exact]
3. Tickets sold for the game = 7,000,000 [approximated]
4. Number of athletes competing = 10, 500 [approximated]
5. Number of sports = 28 [exact] 6. Number of nations competing = 205 [exact]
7. Number of permanent residents in Beijing (2007) = 16,330,000 [approximated]
8. Number of bicycles in Beijing = 10,000,000 [approximated]

By Miss Loh Kwai Yin ( posted in S101 Maths Blog 2011) Maths Teacher of class S1-01 SST 2011

I think Statistics is a means to show the numerical results in a situation over a period of time. Statistics in reality are collect on a real life situation . I think Statistics do lie in certain cases. Statistics are collected so the person providing the statistics may lie or the person drawing up the statistics could lie purposely or accidentally when there is an error along the way of the process of collecting and drawing up a graph or chart to present the data.

Eg: A person is collecting data about the salary of the residents in Block 123. A few residents would not like their actual salary

(II) Learning Experience

My group has decided to work on suggestion 2a) to analysis the data sheet that was consolidated by Ms Loh . Each of us was assigned to be in charge of a zone but our group leader took on the responsibility of two zones . Each of us has to do the statistical analysis , inference and conclusions of the bus services in the zones we were in charged of . We would help  one another when our group members face challenges or problems in the process of generating the information to be put in the poster . We planned the poster together by some discussion of ideas and keeping note of the tips in the presentation slides on the Maths Performance Task Gogglesite .  We had sketch out the layout of the poster on paper .

Our group co-operates and decides on the details as fast as possible . Every member of our team contributes significantly to this project by playing their part in working on the zones to create results for our poster. We are on task.

I am in-charged of the statistical analysis of the North zone. I had to analysis the data and skim out the ideal bus services to analyze . After this , I had to plot graphs based on the data accompanying the bus services. I had  used the statistical process to help me better analyze the data to be able to draw some statistical analysis ,  inferences and conclusions for the graphs .

I was challenged by the requirement to analysis and draw inferences from the data I had to focus on. I was totally at struck at drawing inferences from the strings of numbers and graphs. We found that many of the data of the bus services were invalid for use as they are not accurate . The frequency of the buses in the bus service and the quantity of buses in all the categories of the wait time of the buses does not add up to the same frequency.
Eg :

The frequency of the bus in bus service 262 is 7 . The total number of buses in the wait time columns is 6. It does not add up to the same umber as the frequency .

Simultaneously , other problems like the recurring of the same bus service in some neighborhoods and two of the neighborhoods , West Coast and Marine Parade , has only one valid bus service which failed to meat the requirements of the suggestion 2a) in the scaffolds . We discovered this problem much later so changes have to be make to the graphs and this is very troublesome for us to revert back to the graphs.

I would start the project early and set goals for myself each day to maintain efficient working time. This is so to ensure that not too much time is spent on only one aspect of the project . Look through the requirements of the aspects frequently to keep abide the requirements and ensure that you do not veer off the right path.

Cheng Shu Yu Mavis S1-01

20/5/11 Friday