Data Analysis with Microsoft Excel: Updated for Office 2007

228 Fundamentals of Statistics For example, if you want to construct a confi dence interval around the sample average that will ...

Chapter 6 Statistical Inference 229 Figure 6-3 Using Excel to calculate a confidence interval 8 Close your workbook. You do not ...

230 Fundamentals of Statistics 3 Click Explore the Confi dence Interval from the Table of Contents column. See Figure 6-4. Figur ...

Chapter 6 Statistical Inference 231 By reducing the confi dence interval to 75%, you’ve reduced the width of the confi dence ban ...

232 Fundamentals of Statistics pressure or that polls predict a certain election result, you should ask, “And what is the confi ...

Chapter 6 Statistical Inference 233 There are four elements in a hypothesis test: A null hypothesis, H 0 An alternative hypothe ...

234 Fundamentals of Statistics An Example of Hypothesis Testing Let’s put these abstract ideas into a concrete example. You work ...

Chapter 6 Statistical Inference 235 Let’s apply this formula to our example: m 0550 , s515, n 52 5, and we set a5 0. 0 5 so that ...

236 Fundamentals of Statistics If that were the case, we would not need to double the probability, and the p value would be 0.04 ...

Chapter 6 Statistical Inference 237 3 Click Explore Hypothesis Testing from the Table of Contents column. See Figure 6-7. Figure ...

238 Fundamentals of Statistics The width of the acceptance region shrinks from 11.76 (44.12 to 55.88) with a sample size of 25 t ...

Chapter 6 Statistical Inference 239 Under a one-tailed test, we reject the null hypothesis. Of course, we have to be very carefu ...

240 Fundamentals of Statistics You’ve looked at two approaches to statistical inference: the confi dence interval and the hypoth ...

Chapter 6 Statistical Inference 241 CONCEPT TUTORIALS The t Distribution To see how the t distribution differs from the standard ...

242 Fundamentals of Statistics Working with the t Statistic Excel provides several functions to work with the t distribution. Tw ...

Chapter 6 Statistical Inference 243 of textbooks. If we had used the z test statistic rather than the t statistic in this exampl ...

244 Fundamentals of Statistics the p values returned by the t statistic will still be fairly accurate. As long as the distributi ...

Chapter 6 Statistical Inference 245 There are two observations from each city, and the observations consti- tute paired data. Yo ...

246 Fundamentals of Statistics 2 Verify that the 1-sample t test option button is selected. 3 Click the Input button and then cl ...

Chapter 6 Statistical Inference 247 Figure 6-13 t Test analysis of the labor data t test statistic 95% confidence interval param ...