Open data exploration: Variables analysis

Another way to tackle analysis of the data is to explore the number and nature of the variables being presented. How many variables? What level of measurement? In introductory statistics one is usually either exploring basic statistics, running correlations, or comparing means.

Data is often organized into tables. In statistics columns are often variables while rows are individual data values. This is not always true, but in introductory statistics this is almost always true. If there is a single data column, then there is one variable. If there are two data columns, then there are two variables. The variable name and the units, if any, are usually listed in the first row of the table.

What can be analyzed, what can be done, depends in part on how many variables are present and the level of measurement.

For each of the following data sets, determine the following:

  1. What is the level of measurement?
  2. How many variables are present?
  3. What are the names of the variables - what is being measured?
  4. What statistical functions can be used with the data?
  5. If questions are posed, what is the most appropriate statistical analysis to answer those questions?
  1. Survey results
    Favorite foods survey result
    fish
    fish
    taro
    breadfruit
    banana
    potato salad
    taro
    breadfruit
    rice
    sashimi
    fried shrimp
    banana
    sashimi
    sushi
    sashimi
    pizza
    sphagetti
    fried fish
    pizza
    sushi
    eggs
    rice
    rice
    turkey tail
    lumpia
    fish
    crab
    fried shrimp
    yam
    sardines
    rice
    pizza
    taro
    pizza
    lasagna
    turkey tail
    fried chicken

  2. Favorite foodFrequency
    rice11
    chicken, fried6
    sashimi6
    fish6
    pizza5
    taro5
    spaghetti4
    banana3
    sushi3
    eggs2
    turkey tail2
    shrimp, fried2
    breadfruit2
    potato salad2
    Sum:59

  3. Average amount spent at
    Ace Commercial
    24.33
    24.95
    26.12
    27.75
    28.10
    33.58
    43.11
    47.51
    55.80
    94.33

  4. Operating systemMin Ram Mb
    Apple OS X Lion2000
    Fedora 15 640
    Google Chromium 256
    Haiku OS 128
    Lubuntu 11.04 128
    MS Windows 7 1000
    Red Hat 6 512
    SuSE Linux 512
    Ubuntu 11.04 384
    Xubuntu 11.04 256

  5. Questions:What is the rate of growth for memory requirements for Windows operating systems on a per year basis? What is the trend for the increased memory requirements? Can you predict what Windows 8 will require based on your statistical analysis (use 112 for the year for Windows 8)? Microsoft Windows 8 has a minimum RAM requirement of 2000 Mb. Is this the amount of RAM you predicted?
    Operating systemYearMin RAM Mb
    Win 95 95 4
    Win 98 98 16
    Win Me 10032
    Win XP 10164
    Win Vista106512
    Win 7 1091000

  6. Ocean Energy Kosrae WaveSurfer™ site Ocean Energy Kosrae is an independent power producer in the State of Kosrae. Ocean Energy Kosrae will produce and deliver to the customers in the State of Kosrae electric power harnessed from ocean waves in order to reduce, and ultimately eliminate, the state's dependence on fossil fuels, to improve the quality of life, minimize the cost and expand the use of electricity in the state of Kosrae, to achieve an equal access to affordable and sustainable renewable energy sources in environmentally responsible and commercially viable manner. The state of Kosrae is poised to become the first island in the world to be completely powered by wave energy and other renewable energy sources.

    Two independent samples of wave data were gathered. One sample was from offshore of Malem, and the other was from offshore of Tafunsak. The higher the wave heights, the more power that can be generated.
    Question: Where should the wave generators be placed and why?

    Wave Height (m)
    MalemTafunsak
    1.24.6
    1.73.4
    2.43.7
    2.45.0
    2.54.3
    2.74.3
    2.73.5
    2.94.1
    2.93.6
    2.92.9
    2.93.9
    3.22.9
    3.34.0
    3.32.5
    3.43.1
    3.52.4
    4.03.7
    4.24.8
    4.45.1
    4.74.5

  7. Beauty soaps for women have been around for decades. These also cost more than regular soap. Question: Which soap lasts longer, Dial for Men or Tone? I carefully tracked how long each soap lasted. I was the only one using the bar of soap, and I used the soap every day until it was gone. After about nine months of research, I had the data seen in the table. The data is the duration in days for bars of Dial for Men and Tone. Brandweek, Wash like a man , Dial for men
    Days one bar of soap lasts
    Dial for MenTone
    1410
    139
    1514
    118
    118
    116
    1412
    1413
    1210
    13

  8. Over a year ago, on 03 September 2008 I performed a similar run on a comparable route measuring my split times per kilometer. Determine whether my speed in meters per second has changed from 2008 to 2009. Question:Was I slower in 2009 than in 2008? I ran this study because I turned fifty years old in 2009 (pun intended!).
    Track lap times at the state track
    Speed September 2008 (m/s)Speed October 2009 (m/s)
    2.542.35
    2.542.56
    2.652.42
    2.502.42
    2.552.38
    2.342.28
    2.872.25
    2.652.56
    2.532.06
    3.092.19
    2.49
    2.49