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:
- What is the level of measurement?
- How many variables are present?
- What are the names of the variables - what is being measured?
- What statistical functions can be used with the data?
- If questions are posed, what is the most appropriate statistical analysis to answer those questions?
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| 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 |
-
| Favorite food | Frequency |
|---|
| rice | 11 |
| chicken, fried | 6 |
| sashimi | 6 |
| fish | 6 |
| pizza | 5 |
| taro | 5 |
| spaghetti | 4 |
| banana | 3 |
| sushi | 3 |
| eggs | 2 |
| turkey tail | 2 |
| shrimp, fried | 2 |
| breadfruit | 2 |
| potato salad | 2 |
| Sum: | 59 |
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| 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 |
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- 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 system | Year | Min RAM Mb |
|---|
| Win 95 | 95 | 4 |
| Win 98 | 98 | 16 |
| Win Me | 100 | 32 |
| Win XP | 101 | 64 |
| Win Vista | 106 | 512 |
| Win 7 | 109 | 1000 |
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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) |
|---|
| Malem | Tafunsak |
|---|
| 1.2 | 4.6 |
| 1.7 | 3.4 |
| 2.4 | 3.7 |
| 2.4 | 5.0 |
| 2.5 | 4.3 |
| 2.7 | 4.3 |
| 2.7 | 3.5 |
| 2.9 | 4.1 |
| 2.9 | 3.6 |
| 2.9 | 2.9 |
| 2.9 | 3.9 |
| 3.2 | 2.9 |
| 3.3 | 4.0 |
| 3.3 | 2.5 |
| 3.4 | 3.1 |
| 3.5 | 2.4 |
| 4.0 | 3.7 |
| 4.2 | 4.8 |
| 4.4 | 5.1 |
| 4.7 | 4.5 |
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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 Men | Tone |
|---|
| 14 | 10 |
| 13 | 9 |
| 15 | 14 |
| 11 | 8 |
| 11 | 8 |
| 11 | 6 |
| 14 | 12 |
| 14 | 13 |
| 12 | 10 |
| 13 | |
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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) |
|---|
| 2.54 | 2.35 |
| 2.54 | 2.56 |
| 2.65 | 2.42 |
| 2.50 | 2.42 |
| 2.55 | 2.38 |
| 2.34 | 2.28 |
| 2.87 | 2.25 |
| 2.65 | 2.56 |
| 2.53 | 2.06 |
| 3.09 | 2.19 |
| 2.49 |
| 2.49 |