THE NATIONAL ANTHEM Jana-gana-mana adhinayaka, jaya he Bharatha-bhagya-vidhata. Punjab-Sindh-Gujarat-Maratha Dravida-Utkala-Banga Vindhya-Himachala-Yamuna-Ganga Uchchala-Jaladhi-taranga Tava subha name jage, Tava subha asisa mage, Gahe tava jaya gatha. Jana-gana-mangala-dayaka jaya he Bharatha-bhagya-vidhata. Jaya he, jaya he, jaya he, Jaya jaya jaya, jaya he! PLEDGE India is my country. All Indians are my brothers and sisters. I love my country, and I am proud of its rich and varied heritage. I shall always strive to be worthy of it. I shall give my parents, teachers and all elders respect, and treat everyone with courtesy. To my country and my people, I pledge my devotion. In their well-being and prosperity alone lies my happiness. Prepared by : State Council of Educational Research and Training (SCERT) Poojappura, Thiruvananthapuram - 695012, Kerala. Website : www.scertkerala.gov.in e-mail : scertkerala@gmail.com Phone : 0471 - 2341883, Fax : 0471 - 2341869 Typesetting and Layout : SCERT © Department of Education, Government of Kerala To be printed in quality paper - 80gsm map litho (snow-white) Forward This Textbook of Statistics for Class-XII has been designed to help the students to grasp basic statistical concepts and techniques. Real life opportunities and situations have been provided for applying them in relevant situations. Two major divisions of Statistics namely Descriptive statistics and Inferential statistics were considered while developing this material. The chapters on Descriptive statistics will provide you with a perspective to look at data and to communicate information effectively and efficiently. The chapters on Inferential statistics will tell you, how statistics supplies powerful concepts to estimate the pervasive effect of chance and will help us to generalise beyond limited sets of actual observations. Scopes for doing practicals have also been provided, wherever possible. Novel and emerging ideas and concepts in Statistics have been discussed in the Textbook. This will equip you with a global outlook to enter into the field of statistics, as a professional. The learning outcomes envisaged in each chapter will enable you to look for the purpose of learning each chapter. In the end you can assess yourself - your level in achieving the concepts and ideas. Suggestions and comments about this book are most welcome. Dr. S.Raveendran Nair Director SCERT; Kerala Textbook Development Team 1. 2. 3. 4. 5. MANOJ. K HSS Panagad , Thrissur. ANWAR SHAMEEM. Z. A GHSS Kuttiadi, Kozhikode. SAJISHKUMAR. M MNKM HSS, Chittilamchery, Palakkad. BIJU . G. V GHSS Kulakkada, Kollam. SREESAN.M.B Karimpuzha HSS, Thottara Palakkad. 6. MOHAMMED ASLAM.K PPM HSS Kottukkara, Malappuram . 7. MARY GEORGE St. Raphael’s CGHSS, Ollur, Thrissur. 8. DEEPA KOSHY PSVPM HSS, Ayravon, Pathanamthitta. 9. HASIM. M. C GHSS Aroli, Kannur 10. SAKKEER.M Govt. VHSS Meppayyur, Kozhikode. Experts P.K. VENUGOPAL Associate Professor (Rtd.), Department of Statistics Sree Kerala Varma College, Thrissur. Dr. K. K. HAMSA Associate Professor, Department of Statistics Farook College, Kozhikode. Dr. C. GOKULADASAN PILLAI Former Curriculum Head, SCERT, Kerala Academic Co-ordinator Dr. Chandini. K. K Head, Higher Secondary and Teacher Training State Council of Educational Research and Training (SCERT), Vidhyabhavan, Poojappura, Thiruvananthapuram-695 012 Contents 1. Correlation Analysis 1.1 1.2 1.3 2. 3 4. 2.1 2.2 Meaning of Regression Linear regression 2.3 Regression equations Elementary Calculus 5.2 29 6. 45 3.4 3.5 Definite Integrals Random Variables 4.6 4.7 Distribution Function 4.5 7. 111 6.1 6.2 Normal Distribution - Concept Normal Probability Density Function 6.3 Standard Normal Distribution Sampling Distributions 7.4 7.5 7.6 8. 85 Binomial Probability Distribution Poisson Probability Distribution Normal Distribution 7.1 7.2 7.3 57 Random Variable Discrete Random Variable Probability mass function (pmf) Cumulative distribution function (cdf) Mathematical Expectation, Mean and Variance Continuous Random Variables 4.4 Discrete Probability Distributions 5.1 Derivative of a Function Second Order Derivative Applications of second order derivatives Integration 4.1. 4.2. 4.3 5. Meaning of Correlation Types of Correlation Methods of Studying Correlation Regression Analysis 3.1 3.2 3.3 7 Parameter and statistic Sampling Distribution Distribution of Sample Mean Central Limit Theorem and its importance Chi - square, t and F distributions Relation among Z, Chi-square, t and F statistics Estimation of Parameters 8.1 8.2 8.3 8.4 129 149 Point Estimation Method of Moments Interval Estimation Confidence interval for the population mean 9. Testing of Hypothesis 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 165 Statistical Hypothesis The Two types of Errors Level of Significance and Power of a Test Test Statistic and Critical Region One - Tailed and Two - Tailed Tests Tests of significance of single mean Tests for significance for equality of two population means (Z test) Chi - square test for independence of attributes 10. Analysis of Variance 207 10.1 Types of Variations 10.2 Causes of Variation 10.3 Assumptions of ANOVA 10.4 One - Way ANOVA 11. Statistical Quality Control 11.1 11.2 11.3 11.4 Meaning of Quality Quality Control Statistical Process Control Variation and Causes of Variation 227 11.5 11.6 11.7 11.8 11.9 11.10 Control Charts Types of Control Charts Construction of Control Charts Control Charts for Variables Control Charts for Attributes Uses of Statistical Quality Control 12. Time Series Analysis 255 12.1 Time Series 12.2 Components of Time series 12.3 Uses of Analysis of Time Series 12.4 Trend Analysis 13. Index Numbers 281 13.1 Classification of Index Numbers 13.2 Types of Index Numbers 13.3 Consumer Price index 13.4 Characteristics of Index Numbers 13.5 Uses of index Numbers Appendix A - Answers Appendix B -Glossary Appendix C - References Appendix D - Statistical Tables 301 305 309 310 Appendix E - R Code 316