TY - BOOK AU - Snedecor, George W. AU - Cochran, William G. TI - Statistical methods SN - 8185938180 U1 - 001.422 PY - 1989/// CY - New Delhi PB - Rajkamal Electric Press KW - Statistics KW - Biometry N1 - Chapter 1. Introduction 1.1 Introduction 1.2 Purpose of this chapter 1.3 Examples of sample surveys 1.4 Problems of sampling 1.5 Biased sampling 1.6 Random sampling 1.7 Tables of random digits 1.8 Sampling distributions of estimates 1.9 Studies of the comparative effects of different agents 1.10 Problems in drawing conclusions from comparative studies 1.11 Effectiveness of the Salk polio vaccine 1.12 Death rates of different smoking groups 1.13 Observational studies 1.14 Summary Chapter 2. Frequency Distributions 2.1 Quantitative data 2.2 Frequency distributions 2.3 Grouped frequency distributions 2.4 Class limits 2.5 Cumulative frequency distributions 2.6 Probability distributions Chapter 3. The Mean and Standard Deviation 3.1 Arithmetic mean 3.2 Population mean 3.3 Population standard deviation 3.4 Two-class populations 3.5 Sample standard deviation _ 3.6 Use of frequency distributions to calculate X and s 3.7 Numerical example 3.8 Coefficient of variation Chapter 4. The Normal Distribution 4.1 Normally distributed populations 4.2 Reasons for use of the normal distribution 4.3 Tables of the normal distribution 4.4 Standard deviation of sample meitns 4.5 Frequency distribution of sample .means 4.6 Three illustrations 4.7 Confidence limits for /t when a is known 4.8 Size of sample 4.9 Student's t distribution 4.10 Confidence limits for n based on th« t distribution 4.11 Experinrental sampling of the r dist ribution 4.12 Sample check on confidence interva 1 statements 4.13 Probability plots 4.14 A finite population simulating the normal Chapter 5. T^ts of Hypothecs 5.1 Introduction 5.2 A test of the mean of a normal population (