14 April (Stem-and-Leaf Task): Which part of the Singapore Island has the best air quality?

Singapore is a garden city with trees planted all over the island to create a green belt that 'regulates' the quality of air in the Singapore island in a 'natural' manner. However, there would be a few days in a year where the quality of the air is affected by the forest fires in the nearby countries:

Reported in the ChannelNewsAsia.com website:
http://www.channelnewsasia.com/stories/singaporelocalnews/view/1087523/1/.html


http://www.channelnewsasia.com/stories/singaporelocalnews/view/1088509/1/.html


PSI stands for 'Pollutant Standards Index'. It is an index developed by the United States Environmental Protection Agency (USEPA) to provide accurate, timely and easily understandable information about daily levels of air pollution.

Click HERE to access the 24-hour PSI readings for Singapore.

Every year, the quality of air in Singapore in months like October is badly affected by forest fires, when compared to other months (when we heard little about such instances taking place in the nearby region).

An estate agent claims that no matter how "polluted" the air is, "Air quality in the eastern part of Singapore is always better than that in the western part of the island." Therefore the price of housing properties at East Coast area is higher than those in Boon Lay.

On the other hand, residents who lived in Singapore over the past 5 years claim that the air quality has worsened over the years, especially in the month of October.

We are going to analyse the data available at the Singapore National Environment Agency (NEA) to help us find out whether the claims are justifiable.

CLAIM No. 1:
"Air quality in the eastern part of Singapore is always better than that in the western part of the island."
  • We are going to make comparison the PSI values (in the east & west part of Singapore) in March 2011.
  • On your own...
    • Refer to the March 2011 data at HERE
    • Using the PSI values in the east and PSI values in the west
      • Illustrate the data using a stem-and-leaf diagram
      • Identify the mode and median PSI value in each area
      • Compute the mean PSI value in each area
      • Compare the data between the eastern and the western parts of the island. What can you conclude about the quality of air between the 2 areas in the month of October?
    CLAIM No. 2:  
    "Air quality has worsened over the years, especially in the month of October"
    • You are going to make comparison between 2 sets of data: PSI values for 2005 and 2010
    • On your own...
      • Refer to the 2005 and 2011 March data at HERE
      • Using the overall PSI values for both years
        • Illustrate the data using a stem-and-leaf diagram 
        • Identify the mode and median PSI value for each year
        • Compute the mean PSI value for each year
        • Compare the data between 2 years. What can you conclude about the quality of air between the 2 years in the month of March? 
    Instructions to complete the work
    • Complete the tasks in the Maths notebook
    • Post your consclusions for both claims under comments.
    • It should look something like this...
      • Claim 1: I (agree/disagree) that the quality of the air in the east is better than the western part of the Singapore island because... {Then you use the data to compare and conclude}
      • Claim 2: I (agree/disagree) that the air in Singapore has become worse over the years because... {Then you use the data to compare and conclude}

      25 comments:

      1. Claim 1:I agree that the quality of air in the east is better than the western part of Singapore island because in the western part of Singapore, the PSI once reached over 40 but not in the eastern part of Singapore.Also, using mode, median and mean, it shows that all three readings for the western part of SIngapore is higher than those in the eastern part of SIngapore.
        Claim 2:I disagree that the air in Singapore has become worse over the yeas because in 2005, the air quality reached to over 60 but in 2011 the air quality reached to a maximum of over 40 which has definitely improved.

        ReplyDelete
      2. Claim 1: I disagree that the quality of the air in the east is always better than the western part of the Singapore island because on certain days, such as 7th March, the PSI of west was lower. However, the PSI of east is mostly better than the west. Its means have a difference of about 1.

        Claim 2: I disagree that the air in Singapore has become worse over the years because the average PSI in 2005 is about 17 higher than the PSI in 2011. Which means the air quality has gotten much better than in the past.

        ReplyDelete
      3. Claim 1: I agree that the quality of air in the east is better than the western part of Singapore island as the maximum and the minimum PSI of the western part of Singapore is greater than the eastern part of Singapore. (Using the mean, median and mode also proves that the eastern part of Singapore has a better air quality than the western part of Singapore.

        Claim 2: I disagree that the air in Singapore has become worse over the years as the maximum and minimum PSI of March 2005 is greater than the maximum and minimum PSI of March 2011.

        ReplyDelete
      4. Claim 1: I disagree that the quality of air in the east is always better than the western part of the Singapore island, as sometimes the psi reading of the east is higher than the west. But most of the times the psi readings for the east are lower than the west.

        Claim 2: I disagree that the air in Singapore has become worse over the years as the mean for 2005 march was higher than the mean in 2011 march.

        ReplyDelete
      5. Claim 1:I agree that the quality of air in the east is better than the western part of Singapore island as the PSI value in the western part of Singapore, had reached over 40 once but not in the eastern part of Singapore.The mode, median and mean also proves that the air quality in the east is better.

        Claim 2:I disagree that the air in Singapore has become worse over the years as the PSI value in 2005 had reached to over 60 but in 2011 the PSI value had only reached to a maximum of over 40 which shows that the air quality had improved.

        ReplyDelete
      6. Claim 1: EASTern part is always better than the western part, as only the western hits to the high number 40, while the eastern part stays at 30+ and has more lower values than western part...

        Claim 2 Singapore's air quality is improving not disproving... as the number value went from 2005 to 2011 improved by about 20 value

        ReplyDelete
      7. Claim 1: The eastern side of the island is less polluted than the west as the PSI of the mode, median, mean, PSI value.

        Claim 2: Singapore's air quality has improved over the years, as the mode, median, and mean of the PSI value of 2005 is higher than in 2011.

        ReplyDelete
      8. Claim 1:I agree that the quality of air in the east is better than the western part of Singapore as in the western part of Singapore, the PSI reached over 40 but in the eastern part of Singapore, it stayed under 40.Using the mean, mode and median, I also found that these 3 values for the eastern part of Singapore was less then the western part of Singapore.

        Claim 2: I disagree that the air in Singapore has become worse over the years as in 2005, the air quality got over 60. However, in 2011 the air quality reached over 40. This shows that the qir quality has improved, and not worsen.

        ReplyDelete
      9. This comment has been removed by the author.

        ReplyDelete
      10. Claim 1:I agree that the quality of air in the East is better than the Western part of Singapore island as the mean PSI value of the east is lower than west.The mode and median also proves that the air quality in the east is better.
        Claim 2: I disagree that the air in Singapore has become worse over the years because the mean PSI in 2005 is higher than the PSI in 2011. Which means the air has become better

        ReplyDelete
      11. Claim 1: I agree that the quality of air in the east is better than the west. The mean average PSI value of the air in the east is lower than the west.

        Claim 2: I disagree that the air quality has become worse as the average mean value of the PSI value in 2005 is higher than in 2011, so the air has become better.

        ReplyDelete
      12. Claim 1: I agree that the quality is better in the east compared to the west of Singapore as the mean, median and mode of the PSI values is all lower in the east than the west.

        Claim 2: I disagree as the mean, median and mode of the PSI values in 2005 are higher than those in 2011.

        ReplyDelete
      13. Claim 1: Disagree. PSI can also be increased due to forest fires' haze
        Claim 2: Disagree. The PSI from 2005 is higher than the PSI from 2011

        ReplyDelete
      14. Claim 1: I disagree that the quality of the air in the east is better than the western part of the Singapore island because of a few of the days, the quality of air in the west is slightly better than the east. But, the quality is the east is mostly better than the west.

        Claim 2: I disagree that the air in Singapore has become worse over the years because based on the means of both 2005 and 2011, the quality in 2011 is better than 2005. 2005's mean was much higher than 2011.

        ReplyDelete
      15. Claim 1:I agree that the quality of air in the east is better than the western part of Singapore island because in the western part of Singapore, the PSI once reached over 40 but not in the eastern part of Singapore. The mode and median also proves that the air quality in the east is better.

        Claim 2: I disagree that the air in Singapore has become worse over the years because the average PSI in 2005 is about 17 higher than the PSI in 2011. Which means the air quality has gotten much better than in the past.

        ReplyDelete
      16. claim 1: Disagree. Occasionally the air in the west is better than the east.
        claim 2: Disagree. The air quality in 2011 is better than 2005

        ReplyDelete
      17. Claim1: Agree. Cause the PSI values is all lower in the east than the west.
        Claim 2: Disagree. There are less burning.

        ReplyDelete
      18. Claim 1: I agree, that quality of air in the east is better than the western part of Singapore because the mean average PSI value of the air in the east is lower than the west.
        Claim 2: I disagree as the PSI values fluctuate.

        ReplyDelete
      19. Claim 1: Agree
        Reason: The mode, mean and median of the eats part of Singapore is greater than the west.

        Claim 2: Disagree
        Reason: The PSI of 2005 was higher(air quality was bad) than 2011

        ReplyDelete
      20. Claim 1: I agree, as the PSI values are all lower in the east than the west. The mode and median also demonstrates that.

        Claim 2: I disagree as 2005 's PSI was higher than in 2011, which states that the air quality did not get worse but actually i got better.

        ReplyDelete
      21. Claim 1:I agree that the quality of air in the east is better than the western part of Singapore as in the western part of Singapore because the mean in the East is lower than the mean in the west indicating that the air in the east is better than the air in the west.


        Claim 2:I disagree that the quality of air hs become worse over the years because the mode, median and mean during 2011 are all lower than the mode, median and mean during 2005 indicating that the air in the east is better than the air in the west.

        ReplyDelete
      22. Claim 1: Agree. The air in the eastern part of Singapore is better than the western part of Singapore as the mean in the east is lower than the west which tells us that the air is better in the east.

        Claim 2. Disagree. The PSI in 2011 has been better than the PSI in 2005 which means the air has gotten better.

        ReplyDelete
      23. Claim 1: Agree. The air in the eastern part of Singapore is better than the western part of Singapore because the overall (mean, median mode) is higher in the eastern part is less than those of west.

        Claim 2. Disagree. The PSI in 2011 is less than the PSI in 2005. It is because the overall (mean, median and mode) for 2011 is lower in value than compared to 2005.

        ReplyDelete
      24. Claim 1: I agree that the quality of air in the east is better than the west. The mean average PSI value of the air in the east is lower than the west.

        Claim 2: I disagree that the air quality has become worse as the average mean value of the PSI value in 2005 is higher than in 2011, so the air has become better.

        ReplyDelete