Romeo's
FAQs in STATS

Frequently Asked Questions
in Introductory Statistics


About The book

Having trouble learning statistics? This book provides easy, step by step, recipes for the material in freshman statistics. Its a book your professor will hate. Its written for students.

The step by step procedures describe how to calculate all statistial quantities without the need for extra software or special statistical calculators. These are ideal for students who want to learn the underlying procedures and arithmetic, or who cannot afford to purchase, for example, a TI-84.

Includes optional technology examples on the TI-84, R, and Excel (where applicable). These optional examples, which can be skipped by students who do not use or require technology in their coursework, provide simple procedures for solving statistical problems.

Contents in Brief: histograms, stem plots, the median, mean, standard deviation, IQR, five number summary, outliers, box and whisker plots, normal distributions, parameters and statistics, central limit theorem, confidence intervals, hypothesis testing, inference on the mean, inference on a proportion, inference on difference of means, inference on difference of proportions, two way tables, marginal distributions, chi square tests, scatter plots, linear regression, correlation. With over 300 exercises.

Audience: students taking freshman statistics for the first time; students returning to take stats after a long break in school; students interesting in basic stats with little formal mathematics background.

Pre-requisite: some high school algebra at the level of being able to read and understand equations with variables in them and fill in the blanks. Algebraic manipulation is not needed to solve the problems or follow the recipes. A typical reader is a student who is ready to enroll in college algebra for the first time.


Contents

Getting Started


1 What is Statistics
1 What are Individuals and Variables?
3 What are Populations and Samples?
4 What are Parameters and Statistics?

Describing Distributions

5 What is a Stem Plot?
6 How Do I Make a Histogram?
7 How Do I Find the Median?
8 How Do I Find the Quartiles?
9 What is the 5 Number Summary?
10 What is the IQR?
11 What is the IQR Rule for Outliers?
12 How Do I Make a Box Plot?
13 How Do I Find the Mean?
14 How Do I Find the Variance?
15 How Do I Find the Standard Deviation?

The Normal Distribution

16 What is a Density Function? What is the Difference Between Distribution and Density?
17 What are Shape, Center, and Variability?
18 What is Normal?
19 What is z?
20 What is the 68-95-99.7 Rule?
21 How Do I Use a Table of the Normal Distribution?
22 How Do I Do a Reverse Lookup in a Table of the Normal Distribution?
23 How Do I Find a Probability for a Normal Distribution?
24 How Do I Find the Probability that a single individual x is smaller than something?
25 How Do I Find the Probability that a Single Individual x is Bigger than Something?
26 How Do I Find the Probability that a Single Individual x is Between Two Values?
27 When Do I Subtract from One?
28 What is the Central Limit Theorem?
29 How Do I Find z*

Inferential Statistics


30 How Do I Find a Confidence Interval On the Mean?
31 How Big Does My Sample Size Have to Be to Do Inference of the Mean?
32 What is a Hypothesis?
33 What is a p-value?
34 How Small is Small? What is alpha? What is the Difference Between p and alpha?
35 How Do I Perform a Hypothesis Test on the Mean?
36 What is the Difference Between Type I Error and Type II Error?
37 What is a t Distribution? What is the Difference Between a Normal and a t Distribution?
38 How Do I Know Whether to Use a z-Statistic or a t-Statistic?
39 How Do I Findt*?
40 How Do I Find the p-Value for a t Distribution?
41 How Do I Find a Confidence Interval When I Don’t Know the Population Standard Deviation?
42 How Do I Do a Hypothesis Test When I Don’t Know Standard Deviation of the Population?
43 Should I Do Matched Pairs or a Difference of Means?
44 How Do I Find a Confidence Interval Using Matched Pairs Data?
45 How Do I Perform a Hypothesis Test on Matched Pairs Data?
46 How Do I Find the Degrees of Freedom (df ) for a Difference of Means Test?
47 How Do I Find a Confidence Interval for the Difference of Two Means?
48 How Do I Do a Hypothesis Test for the Difference of Two Means?
49 How Do I Find A Confidence Interval on a Proportion?
50 How Do I Do A Hypothesis Test on a Proportion?
51 How Big Does My Sample Size Have to Be to Do Inference on A Proportion?
52 How Do I Find A Confidence Interval on a Difference in Proportions?
53 How Do I Do a Hypothesis Test on the Difference Between Two Proportions?

Comparing Variables


54 How Do I Find The Marginal Distribution in a Two Way Table?
55 How Do I Calculate Expected Values in a Two-Way Table?
56 What is a Chi Squared Test of Independence?
57 What is a Chi Squared Homogeneity Test?
58 What is a Chi Squared Goodness of Fit Test?

Describing Relationships

59 What is a Scatter Plot?
60 What is the Correlation?
61 How Do I Find the Correlation?
62 How Do I Do Linear Regression?
63 How Do I Calculate the Predicted Value in a Linear Regression? 64 What is a Residual

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