Descriptive Statistics for Data Analytics/Science

Basically descriptive statistics tells everything about the data that is available, it doesn’t tell us anything out of that data.

So how to describe the (Numerical/Categorical) data?

- graphical representation 

- tabular representation

- summary statistics 

Type of variables in statistics-

1) Numerical or Quantitative (continuous and discrete)

2) Categorical or Qualitative (only discrete)

- nominal

- ordinal

Speaking about variables they can be single or multiple as 

We deal with data in descriptive statistics, it is important to establish relationship between this variables so as to summarize.

• Graphical representation- Single variable

- For Categorical(Qualitative) variables:

-> Bar Graph: suited for ordinal variables 

-> Pie Chart: suited for nominal variables

- For Quantitative(Numerical) variables:

-> Box-plot( suited for continuous data)

-> Histogram(1st step to start before distribution)

-suited for discrete data

• Graphical Representation: Multiple variables

- Scatter plots-> two quantitative (numerical) variables

- Box-plots-> one categorical (qualitative) other quantitative variable (Suited for continuous data)

- Contingency table -> both categorical with frequency of occurrence of both.

• Measures of Central Tendency: 

How to summarize data through numbers?(summary statistics)

- Measures of central tendency (mean, mode, median)

- Dispersion

- Skew and Kurtosis

Choosing when to use mean, median:

- bad outlier

- good outlier

When to use Mode:

- useful with nominal variables 

- multi modal distribution

• Measures of dispersion:

- Range (Max- Min)
- InterQuartile Range (IQR) = 3rd Quartile - 1st Quartile or (75th percentile - 25th percentile) 
- Sample Standard Deviation
- Variance
- Mean Absolute Deviation

 All Formulas:

How Amazon Echo works??

The amazon echo is a smart IOT device which listens to your voice and translates it into commands to perform tasks such as Turn ON/OFF lights, playing music, ordering products from amazon, setting alarm, etc. Read this blogpost to know how it works!!!

What is Amazon Echo?

Amazon echo is a device which uses speech recognition to perform tasks, the actual brain which performs these tasks is Alexa. Alexa  uses a small computer along with microphones, speakers, and cloud computing (AWS). It performs a wide range of tasks using the 'Internet'. All you need is smart devices around you to make use of the echo fully. 

How Echo/Alexa works?

Echo is always ON, it connect's to the home wifi and stays ON. When you say something "Alexa..." it wakes up, Alexa records that voice and internally gathers voice commands and send them to the natural langauge voice recognition service in the clouds called Alexa Voice Service it interprets the commands and sends back the result.

Check this graphical representation to know how it works.

 What are Alexa compatible devices?

• Echo
• Echo dot
• Echo show
• Echo spot
• Echo plus
• Echo Input
• Echo Show 5
• Echo Tap

Buy Echo devices from amazon Buy here

What all home devices are compatible with Alexa other than Echo (smart speaker)?

Arlo Q - Smart Camera buy here

Ecobee (5th gen) - smart thermostat buy here

Philips hue white A19 starter kit - smart lights  buy here

Check this post for more updates about amazon Alexa. 

Delete the Cam scanner app now!!!

Your portable mobile scanner is infected with malware!!

We come across many apps in our smart phones which triggers lots of advertisements(almost all free apps). As we tend to use free version of apps, we don’t have privilege to disable the Ads. If you want seamless ad free experience you need to spend bucks for purchasing the premium version of app. Recently cam scanner was surrounded with new controversy which looks very scary‼️‼️

Cam Scanner has been removed from the plays store!!

The malware is Trojan Dropper, it’s a software which runs and downloads additional modules on the smartphone without the user consent. In case of cam-scanner the malware runs multiple ads on the phone  and make user signup for paid services without there knowledge. Now let’s understand in layman terms how critical is this issue!!!

What is Malware?

Malware is a program/file that is harmful to a computer/smartphone user. Malware can be viruses, worms, Trojan horses or spyware. This program performs different types of functions like stealing user data, taking control over a specific computer function or system. Malware can monitor or even delete sensitive data without user's permission.

What is Cam scanner?

It's a widely used mobile app which converts your phone into a portable scanner. It helps to scan documents, ID's, images etc. It automatically crops the edges and enhance the scanned document. It has more than 100 million downloads on play store.

Why should I uninstall the Cam scanner app(Android users)?

Prior to uninstalling the app you should first take backup of your important scanned data in the app. 

Steps To take backup of your files from Camscanner:

Click on the link and follow the steps: https://www.camscanner.com/mobile/faq?type=sync_and_backup&id=62

Till now the app was running smoothly but in recent versions of the app the security researchers have found malicious malware which was contained in app's advertising library, this malware is known as Trojan-Dropper.AndroidOS.Necro.n. So what this Trojan malicious code does is downloads more malicious codes into your smartphone and make you sign up into paid services without your knowledge!!

You should delete the app from your phone until the app developers officially announce and upload a stable malware free version on the play store.

• There are many old versions of the app on play store like Cam Scanner HD etc. but you should avoid downloading such versions as it may contain the malicious code.
• The ios users don't need to worry about this as due to apple's strict privacy policy the app won't affect the apple users and it's malware free.

What if i need the stable malware free version ?

If you still need malware free version now, download the apk file provided by camscanner. 
Download the malware free apk file now by clicking this link- https://t.co/79tt0IrMdw

Official Statement from Camscanner:

Steps To take backup of your files from Camscanner:

Click on the link and follow the steps: https://www.camscanner.com/mobile/faq?type=sync_and_backup&id=62

All users should be cautious about the usage of app if you have scanned your sensitive documents please move them to different location than delete the app, your data is your identity.