Estatística básica minitab

Páginas: 56 (13963 palavras) Publicado: 11 de julho de 2012
CONTENTS

INDEX

MEET MTB

UGUIDE 1

UGUIDE 2

SC QREF

HOW TO USE

1
s s s s s s s s s s s s s s

Basic Statistics
Basic Statistics Overview, 1-2 Descriptive Statistics Available for Display or Storage, 1-4 Display Descriptive Statistics, 1-6 Store Descriptive Statistics, 1-9 One-Sample Z-Test and Confidence Interval, 1-12 One-Sample t-Test and Confidence Interval, 1-15Two-Sample t-Test and Confidence Interval, 1-18 Paired t-Test and Confidence Interval, 1-22 Test and Confidence Interval of a Proportion, 1-26 Test and Confidence Interval of Two Proportions, 1-30 Test for Equal Variances, 1-34 Correlation, 1-37 Covariance, 1-41 Normality Test, 1-43

MINITAB User’s Guide 2

1-1

CONTENTS

INDEX

MEET MTB

UGUIDE 1

UGUIDE 2

SC QREF

HOW TO USE CONTENTS
Chapter 1

INDEX

MEET MTB

UGUIDE 1

UGUIDE 2

SC QREF

HOW TO USE
Basic Statistics Overview

Basic Statistics Overview
Use MINITAB’s basic statistics capabilities for calculating basic statistics and for simple estimation and hypothesis testing with one or two samples. The basic statistics capabilities include procedures for
s s s

calculating or storing descriptivestatistics hypothesis tests and confidence intervals of the mean or difference in means hypothesis tests and confidence intervals for a proportion or the difference in proportions hypothesis test for equality of variance measuring association testing for normality of a distribution

s s s

Calculating and storing descriptive statistics
s

Display Descriptive Statistics produces descriptivestatistics for each column or subset within a column. You can print the statistics in the Session window and/or display them in a graph. Store Descriptive Statistics stores descriptive statistics for each column or subset within a column.

s

For a list of descriptive statistics available for display or storage see page 1-4. To calculate descriptive statistics individually and store them asconstants, see the Calculations chapter in MINITAB User’s Guide 1.

Confidence intervals and hypothesis tests of means
The four procedures for hypothesis tests and confidence intervals for population means or the difference between means are based upon the distribution of the sample mean following a normal distribution. According to the Central Limit Theorem, the normal distribution becomes anincreasingly better approximation for the distribution of the sample mean drawn from any distribution as the sample size increases.
s

1-Sample Z computes a confidence interval or performs a hypothesis test of the mean when the population standard deviation, σ, is known. This procedure is based upon the normal distribution, so for small samples, this procedure works best if your data were drawn froma normal distribution or one that is close to normal. From the Central Limit Theorem, you may use this procedure if you have a large sample, substituting the sample standard deviation for σ. A common rule of thumb is to consider samples of size 30 or higher to be large samples. Many analysts choose the t-procedure over the Z-procedure whenever σ is unknown.
MINITAB User’s Guide 2

1-2CONTENTS

INDEX

MEET MTB

UGUIDE 1

UGUIDE 2

SC QREF

HOW TO USE

CONTENTS

INDEX

MEET MTB

UGUIDE 1

UGUIDE 2

SC QREF

HOW TO USE
Basic Statistics

Basic Statistics Overview
s

1-Sample t computes a confidence interval or performs a hypothesis test of the mean when σ is unknown. This procedure is based upon the t-distribution, which is derived from a normaldistribution with unknown σ. For small samples, this procedure works best if your data were drawn from a distribution that is normal or close to normal. This procedure is more conservative than the Z-procedure and should always be chosen over the Z-procedure with small sample sizes and an unknown σ. Many analysts choose the t-procedure over the Z-procedure anytime σ is unknown. According to the Central...

Por favor, assinar para o acesso.