Pack 2023
LATEST QUESTIONS
AND ANSWERS
,Department of Statistics
STA1502
Statistical inference I
Study guide for STA1502
, i STA1502/1
CONTENTS
Orientation iii
STUDY UNIT 1
1.1 Introduction 1
1.2 Inference about the Difference Between Two Population Means: 1
Independent Samples
1.3 Observational and Experimental Data 18
1.4 Inference about the Difference Between Two Population Means: 19
Matched Pairs Experiment
1.5 Inference about the Ratio of Two Variances 28
1.6 Self-correcting Exercises for Unit 1 38
1.7 Solutions to Self-correcting Exercises for Unit 1 39
1.8 Learning Outcomes 46
STUDY UNIT 2
2.1 Introduction 48
2.2 Inference about the Difference Between Two Population Proportions 48
2.3 One-Way Analysis of Variance 57
2.4 Multiple Comparisons 68
2.5 Analysis of Variance experimental designs (read only) 80
2.6 Randomized Block(two-way) Analysis of Variance 81
2.7 Self-correcting Exercises for Unit 2 87
2.8 Solutions to Self-correcting Exercises for Unit 2 89
2.9 Learning Outcomes 98
STUDY UNIT 3
3.1 Chi–square test 100
3.2 Chi-squared goodness-of-fit test 101
3.3 Chi-squared test of a Contingency Table 107
3.4 Summary of test on nominal data 109
STUDY UNIT 4
4.1 Simple linear regression and correlation 118
4.2 Simple Linear Regression and Correlations 118
4.3 Diagnostic Tools for checking the regressionassumptions 122
STUDY UNIT 5
5.1 Non parametric statistics 131
5.2 The Wilcoxon Rank Sum Test: Independent Random Samples 131
, ii
5.3 Sign Test and Wilcoxon Signed Rank Sum Test 137
5.4 The Wilcoxon Signed Rank Sum Test for a matched paired experiment 147
5.5 The Kruskal–Wills H –test for completely randomized designs 151
5.6 Friedman Test for the Randomized Block Design 154
STUDY UNIT 6
6.1 Introduction 158
6.2 Components of time series 158
6.3 Smoothing techniques 160
6.4 Trend and seasonal effects 164
6.5 Introduction to forecasting 167
6.6 Forcasting models 167