Tutorials on Data Science
Charts and Graphs in Excel
Charts and graphs are used to make information clearer and easier to understand. A good picture is worth a thousand numbers. The most common place for people to see charts and graphs is in the news. News publishers use graphics all the time to show comparisons and explain important trends for things such as weather, gas prices,…
Excel: DATA VALIDATION
Data validation feature allows you to set up certain rules that dictate what can be entered into a cell. It allows you to do the following: Make a list of the entries that restricts the values allowed in a cell. Create a prompt message explaining the kind of data allowed in a cell. Create messages…
Descriptive Statistics in R
Descriptive statistics is the term given to the analysis of data that helps, describe, show or summarize data in a meaningful way, It doesn’t allow us to make conclusion beyond the data we have analyzed or reach the conclusion regarding any hypothesis we have made. There are generally two types of statistics:- Measures of central…
EXCEL : Importing External Data
External data is defined as data that exists outside of the Excel workbook, in some other place. Other places could be almost anywhere; and Excel supports pulling external data from a wide variety of sources. Examples include data stored on web pages, in text files, or in other programs. Excel 2007 is been used in…
Excel: Functions-II
TEXT FUNCTIONS 1. TRIM: Removes all spaces from a text string except for single spaces between words SYNTAX: =TRIM (text) TEXT: Required. The text from which you want spaces removed. EXAMPLE: 2. LEN: Returns the number of characters in a text string SYNTAX: =LEN (text) TEXT: Required. The text whose length you want to…
Excel: Functions
MATHEMATICAL FUNCTION 1. SUM: Sum function is used to calculate a simple total for a range of numeric cells. SYNTAX: =SUM (number1, [number2], …) EXAMPLE: Add numbers stored in cell from cell numbers D1 to D4. 2. SUM PRODUCT: Returns the sum of the products of corresponding ranges of array SYNTAX: =sum product (array1, array2, [array3],…)…
T – Test
Introduction An Irish statistician, W.S. Gossett in 1908, applied this test for test for testing the significance of difference between the means of two different samples of small size. It was named ‘t-test’. The pen name of Gossette was student, hence this test is called Student’s ‘t’ test. Student t-test is also described as t-distribution…
Excel : SORT AND FILTER
Sorting: The literal meaning of sorting is to rearrange the stuff in a desired manner. The exactly same facility is provided by MS Excel to sort the data. While sorting a table, we rearrange the rows based on the contents of a particular column for example we need to sort a table in such a…
Excel: WHAT-IF ANALYSIS
One of the most appealing aspects of Excel is its ability to create dynamic models. A dynamic model uses formulas that instantly recalculate when you change values in cells that are used by the formulas. When you change values in cells in a systematic manner and observe the effects on specific formula cells, you’re performing…
Test Of Hypothesis
1. Introduction to Hypothesis Testing A hypothesis, in statistics, is a statement about a population where this statement typically is represented by some specific numerical value. 2. Types of Hypotheses Hypothesis testing is formulated in terms of two hypotheses: H0: the null hypothesis H1: the alternative hypothesis. 3. Steps for Testing the Hypothesis In hypothesis testing…
