Wednesday, 9 October 2013

Aditya Shinde
Roll no 1
Group 1
Stratified Random Sampling
1)More often than not, you will not only want to examine the results from the overall population, but also understand the differences between key demographic subgroups within the population.
2) For example, you might want to understand the differences between different groups of employees, like senior managers vs. regular employees.
3) If you plan to look at distinct subgroups such as these, you should perform a stratified random sample. In a nutshell, this means you will need to select a separate random sample from each of the subgroups rather than just taking a single random sample from the entire group.
4)The process is slightly more time consuming and will require you to survey a greater number of people overall, but this technique can be very valuable. 

5)If you want to conduct a stratified random sample, think carefully about the single most relevant demographic division that can be made between people within your population.
6) It is probably not practical to conduct a stratified random sample on more than one demographic category as the process becomes much more complex and you will ultimately end up needing to survey almost the entire population if any of the subgroups are very small.

7) For example, if you wanted to look at employee survey results and by level and job function, you would need to look at each level/function combination and you might find very small numbers of employees within some of these areas. 

Monday, 16 September 2013


Aditya Shinde

Group 1

Roll No 1

 Stem and Leaf Diagram

A Stem and Leaf Diagram displays quantitative data in graphical format . If is called a stem and leaf diagram because it represents a shape of a tree and its branches when data is categorically posted .

           

Steps for Stem and Leaf Diagram

1)      The data must be sorted in ascending order. This will help in easy differentiation of data so that we are able to define parameters for stem and accordingly its leaves.

2)      Generally it is advisable that stems represent the first digit of the number and leaves represent the unit digit of the number.

Limitations of Stem and Leaf Diagram

1)      One of the limitations of Stem and Leaf diagram is that it is only effective in the case of limited data as large quantity of data would be difficult to differentiate and record.

2)      Also data which is more than two digits is also difficult to record in Stem and Leaf  format.

Example

10,12,15,18,21,26,28

Solution

1-      0,2,5,8

2-      1,6,8

This data shows list of numbers included in tens and twenties sorted as per Stems and Leaf Diagram.

 

 

 

                                                                Source- www.wikipedia.com