# A great example to show power of visualizing data: Anscombe’s Quartet Table

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Let’s look at four datasets which have identical statistical properties:
Here’s the DATA:

PropertyValue
Mean of x in each case9 (exact)
Variance of x in each case11 (exact)
Mean of y in each case7.50 (to 2 decimal places)
Variance of y in each case4.122 or 4.127 (to 3 decimal places)
Correlation between x and y in each case0.816 (to 3 decimal places)
Linear regression line in each casey = 3.00 + 0.500x

They look identical – don’t they? BUT let’s visualize the data: Only visualizing data made it possible for us to understand and appreciate the “difference” between data-sets. Looking at just statistical properties made them appear “similar” – moral of the story: Visualize data! Graph data along with investigating statistical properties.

Source: Anscombe’s quartet

# Data Reporting ≠ Data Analysis

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One of the key thing I’ve learned is importance of differentiating the concepts of “Data Reporting” and “Data Analysis”. So, let’s first see them visually: Here’s the logic for putting Data Reporting INSIDE Data Analysis: if you need to do “analysis” then you need reports. But you do not have to necessarily do data analysis if you want to do data reporting.

From a process standpoint, Here’s how you can visualize Data Reporting and Data Analysis: We need it because TOOLS are really great at generating data reports. But it requires a HUMAN BRAIN to translate those “data points/reports” into “business insights”. This process of seeing the data points and translating them into business insights is core of what is Data Analysis. Here’s how it looks visually: Note after performing data analysis, we have information like Trends and Insights, Action items or Recommendations, Estimated impact on business that creates business value.

#### Conclusion:

Data Reporting ≠ Data Analysis

# Adding a TrendLine to a Time Series Line Chart in Excel 2010:

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I was playing w/ a time series data set in Excel 2010 and learned how to add a Trend-line and in this blog post, I’ll share how I added it:

First up, How is Trend-line useful? Here are few answers:
– It helps us see how data is changing over time, in other words, it helps us find “trends”
– It helps us forecast future.

Now let’s add the trend-line and you’ll be able to compare on your own how Trend-line makes it easier to spot “trends”. Here are the steps:

1. select the line > right-click > add trend line 2. configure the trend-line options 3. I also changed the line style

4. And Here’s the chart w/ trend-line Conclusion:

In this post, we saw how to add trend-line in the time series chart in excel 2010

# Statistics 101: Nominal, Ordinal, Interval, Ratio Data

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If you work with any statistical analysis tool, sometimes you may have run into configuring the data into either of these following categories: Nominal, Ordinal, Interval, Ratio

Here is what each term means:

 Nominal Simply names or call them set of characters Example: Full name, fruits, cars, etc Ordinal Nominal + They have order Example: Small, medium, big Interval Ordinal + the intervals between each value are equally split Example: temperature in Fahrenheit scale:10 20 30 etcNote that 20F is not twice as cold as 40F. So multiplication does not make sense on Interval data. But addition and subtraction works. Which brings us to next point: Ratio Ratio Interval + multiplication makes sense Weight: 60KG, 120KG.120 KG = 2 * 60 KG

I hope the examples are of help when you are working with statistical analysis tools and need to categorize the data.