Advertisement

Advertisement

Saturday, January 14, 2017

STATISTICS(basic concept) NOTES for RRB NTPC EXAM

The words ‘Statistics’ appears to have been derived from the latin word ‘status’ meaning a (political) state. In its origin, Statistic was simply the collect of data on different aspects of the life of the people.

Statistics deals with data collected for specific purposes. We can make decisions about the data by analysing and interpreting it.

Central line tendency

Mean: The mean or average of a number of observation is the sum of the value of all the observation divided by the total number of the observations.

It is denoted by the symbol,  read as x bar

Here n is a number of observation.

Example- people were asked about the time in a week they spend in doing social work in their community. They said 10, 7, 13, 20 and 15 hours respectively.Find the mean (or average) time in a week devoted by them in social work.

Sol. The mean =(Sum of all the observations)/(Total number of observations)

=(10 + 7 + 13 + 20 + 15)/5=65/5=13 

So, the time spent by these 5 people in doing social work is 13 hours in a week.

The median- the median is that value of the given number of observations, which divide it into exactly two parts.  when the data is arranged in ascending or decreasing order.

The median of ungrouped data is calculated as follows:

(i) When the number of observation (n) is odd, the median is the value of the ((n+1)/2)ith observation.    

Example: If n = 15, the value of the ((15+1)/2)ith i.e. the 8th observation will be median

(ii) When the number of observation (n) is even, the median is the mean of the (n/2)ith and (n/2+1)ith observations.

Example: If n = 16 the mean of the value of the (16/2)ith and (16/2+1)ith observations. 

Example: The height (in cm) of 9 students of a class follows.

155, 152, 160, 144, 145, 148, 150, 147,149

Find the median of the data

Sol. Arrange the data in ascending data

144, 145, 147, 148, 149, 150, 152, 155, 160

Since the number of students is 9, an odd number.

Median is the height of the   = 5th student which is 149 cm

So, median = 149 cm

 Modes: The mode is that value of the observation which occurs most frequently i.e. an observation with the maximum frequency is called the mode.

Example: Find the mode of the following marks (out of 10) obtained by 20 students.

4, 6, 5, 9, 3, 2, 7, 7, 6, 5, 4, 9, 10, 10, 3, 4, 7, 6, 9, 9

Sol. We arrange this data in the following form:

2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 9, 9, 9, 9,10, 10

Here 9 occurs most frequently i.e. four times. So, the mode is 9.

No comments:

Post a Comment

IF YOU LIKE THE POST,PLEASE LIKE FACEBOOK PAGE BELOW.

KINDLY POST YOUR COMMENT BELOW.

Labels

2 step varification (3) 2014 (2) aam aadmi party (3) AAP KI SAMSYA (2) Aashiqui 2 (1) AB De Villiers (1) AB Devilliers (1) Abdul Kalam (1) Adblock plus (1) Adblocker (1) adhitz (3) admission (1) advertising (4) affair (1) Afghanistan (2) aishwarya (1) Ajay Devgan (1) Akshay kumar (1) alert (3) Alia Bhatt (1) amazon (4) america (22) amir khan (3) Amitabh bacchhan (6) Anand Kumar (1) anil ambani (2) animals (1) application (3) aptitude (2) Argentina (1) Arjun Kapoor (1) Article (57) arvind kejriwal (5) Assam (1) atcontent (11) attraction (1) Australia (5) australia cricket (6) Bang Bang (1) Bangladesh (3) Bank (1) bank exams (21) banking (1) Banks (1) Bawana Depot (2) Beauty (3) Belgium (1) benny dayal (1) bharat sarkaar (4) Big Billion Day (1) Bigg Boss (2) biology (2) biotechnology (3) Bipasha Basu (3) BJP (3) Blackberry (1) blog (3) blogger (19) blogging (17) bollywood (88) book (2) Boys/Girl (1) Boys/Girls (110) brazil (4) business (46) business studies (4) buysellads (1) Byomkesh bakshi (1) camera (1) car (1) Cars (1) cat (3) cbse (8) celebrity (18) celebs (87) champions league (1) chemistry (3) chennai express (1) Chennai Super kings (3) chetan bhagat (2) children (2) chitika (4) Christmas Day (1) chutiyapa (8) civil services (1) clickbank (1) clicksor (4) clixgalore (1) clixsense (1) coco (1) college (89) comedy circus (1) comedy nights with kapil (8) competitive exams (84) computer (6) Congress (1) content marketing (2) controversy (11) Corey Anderson (1) costa rica (1) cricket (55) crime (1) dailymotion (2) Danielle Wyatt (1) dating (1) DD national (1) Delhi (20) Delhi Daredevils (2) Delhi metro (6) Delhi technological university (6) Delhi University (3) Dev Anand (1) Dilip kumar (1) Diwali (1) doctor (2) donate (1) Download (2) download youtube videos (1) DTC (5) Earn money (53) ebay (2) ebiz (2) economics (2) Education (64) ekta kapoor (1) Engineering (2) England (6) England Cricket (2) England Women cricket (2) English (5) Eve teasing (1) exams (16) Facebook (11) Facebook likes (1) family (1) FilmFare (1) Finance (5) Flickr (1) flipkart (6) football (8) Formula1 (1) France (1) friends (1) galaxy (1) Game of Thrones (1) GATE (1) Gautam gambhir (1) General (92) geography (1) George Bailey (1) Germany (2) GitHub (1) GK (179) Glenn Maxwell (1) Gmail (2) godaddy (5) Google (25) Google adsense (9) Google Trends (4) google+ (3) GoogleDNS (1) GOSF (1) Graeme Swann (1) Grand masti (1) graphic card (1) Greg Chappel (1) Gunday (1) Half Girlfriend (1) handball (1) Haryana (1) Haryana sarkar (1) haryanvi movie (1) hash tag (1) Hate story 2 (1) Health (25) hindi (5) History (3) Holland (1) Hollywood (10) homeshop18 (2) Honey Singh (2) Hongkong (1) Hrithik Roshan (1) Human Psychology (1) Humor (14) humour (9) ibps (4) icc (3) ICC World Cup (3) ICC World Cup 2015 (3) IIIT Allahabad (4) IIM (2) iit (2) India (272) India Railways (6) Indian cricket (21) Indian Share Market (1) Indian States (21) Indian Stock Market (1) Indiblogger (1) infibeam (2) infolinks (3) internet (120) Interview Tips (1) investment (2) ipl (7) Ireland (2) irfan khan (1) izea (1) jabong (2) Jacques Kallis (1) James Rodriguez (2) John Abraham (1) Jules Bianchi (1) Kailash Satyarthi (1) kamaal khan (2) kapil sharma (10) Karan Johar (1) Karan Singh Grover (1) kareena kapoor (1) katrina kaif (3) Kevin Peterson (2) kick (2) Kim Kardashian (1) Kings XI punjab (2) Kolkata Knightriders (4) kontera (3) L'Oreal (1) laptop (2) leadership (1) lenskart (1) Life (123) linkshare (3) LL (22) Lords (1) lottery (3) love (28) Love Proposal (2) Luis Suarez (1) Madras Cafe (1) Mahabharat (1) mahendra singh dhoni (5) Malala (1) Maria Sharapova (1) Mario Gotze (1) Mark Zuckerberg (2) marketing (1) Mary Kom (1) Mayanti langer (2) medical (4) mens (3) messaging sites (1) metrogirl (1) mexico (1) michael clarke (1) Michael Phelps (1) Michael Schumacher (1) Microsoft (3) Microsoft Word (1) mobile (15) Money (4) monkey (1) Motivational (83) movie (18) movie review (14) MS Dhoni (5) Mukesh Ambani (2) Mulayam Singh (1) Mumbai Indians (2) music (1) mussoorie (1) myntra (1) naaptol (1) Narendra Modi (13) NASA (1) Nepal (1) New zealand (2) New Zealand cricket (1) news (18) Newspaper (16) Neymar (1) nigeria (1) NNMCB (2) Nobel Prize (1) Noble cause (1) nokia (1) non-profit cause (1) Notes (3) Novak Djokovic (1) Ochoa (1) olx (1) Olympics (1) online education (15) online popularity (2) online shopping (1) orkut (1) Paksitan (2) parents (1) Pastebin (1) pc (6) Personal Finance (1) Phillip hughes (3) photography (1) Physics (1) pinterest (1) pk (1) political science (1) politics (11) Priyanka Chopra (2) Psychology (5) qadabra (1) quantitative aptitude (6) Query (49) quikr (1) Quotation (13) Quotes (36) Rahul Dravid (2) Rajasthan Royals (2) Rajesh khanna (1) Rajsthan (1) Ram charan Teja (1) Ranveer singh (1) rape (5) Ray Rice (1) Real madrid (1) Reasoning (5) Record (1) redirect url (1) relationships (3) Reliance (1) Republic Day (1) Richard Sherman (1) Roger Fedrer (1) Rohit Sharma (2) Royal challenger Bangalore (2) Sachin tendulkar (9) Sadashiv Amrapurkar (1) saif ali khan (1) sales (1) Salman khan (10) samsung (2) Sanjay Dutt (1) Santa Clause (1) Sarah Taylor (1) Scams (7) Scandal (2) ScaryBasu (1) schoolboy (2) schools (6) science (1) search engine optimization (2) Selfie (3) semester (1) seo (2) sex (6) sexy girls (8) Shahid Kapoor (1) shahrukh khan (6) shame (1) Shane warne (1) Shane Watson (1) Share Market (2) Shehnaz treasury (1) Shikhar Dhawan (1) Shradha kapoor (2) singham returns (1) smartphone (1) sms (1) snapdeal (2) social network (21) societies (2) software (3) sonakshi sinha (1) Sonia Gandhi (1) South africa (3) South Africa Cricket (3) spiritual (1) sponsored (1) sports (13) Sri Lanka (3) Sri Lanka Cricket (2) ssc (40) starcj (1) stock market (29) stuart binny (3) students (171) Sunil Shetty (1) sunny leone (3) Sunrisers Hyderabad (2) Suresh Raina (3) surveen chawla (1) survey extreme (1) syllabus (2) T20 (5) T20 World Cup (3) Tamilanadu (1) Teacher (2) teaser (1) Tech (37) Technology (1) Television (3) Tennis (2) test cricket (2) The Hindu Editorial (33) tiger (1) tips (1) Top10 (3) torrent (1) tour (3) Trailer (5) travel (5) tricks (2) Trolls (22) tutorials (20) TV (2) twitmob (1) twitter (10) UAE (1) Updates (71) upsc (6) uttar kumar (1) Uttar Pradesh (1) Varun Dhawan (1) videos (2) Vimeo (1) viral (15) Virat Kohli (5) Virendra sehwag (1) vivek oberoi (1) Vivid (5) warren buffet (1) Web browsing (1) webs (2) website (24) Weebly (1) West indies (2) whatsapp (4) white revolution (1) Wikipedia (1) Wimbledon (1) Windows (2) wordpress (8) world (134) world cricket (2) world cup (7) world cup 2014 (4) Yahoo (1) Youth (1) Youtube (12) YouTube Channel (3) Yuvraj Singh (3) Zanjeer (2) Zee news (2) Zimbabwe (1) zoo (1)