<p>Chapter 11 Inferences on Two Samples </p><p>Ch 11.1 Inference about Two Population Proportions</p><p>Objective A : Distinguish between Independent and Dependent Sampling</p><p>Example 1: Determine whether each sampling method is independent or dependent.</p><p>(a) Test scores of the same students in English and Math.</p><p>(b) The effectiveness of two different diets on two different groups of </p><p> individuals. Objective B : Test Hypotheses or Confidence Intervals Regarding Two Proportions from Independent Samples</p><p>Example 1: The drug Prevnar is a vaccine meant to prevent certain types of bacterial meningitis. It is typically administered to infants starting around 2 months of age. In randomized, double-blind clinical trials of Prevnar, infants were randomly divided into two groups. Subjects in group 1 received Prevnar, while subjects in group 2 received a control vaccine. After the second dose,</p><p>137 of 452 subjects in the experimental group (group 1) experienced drowsiness as a side effect. After the second dose, 31 of 99 subjects in the control group (group 2) experienced drowsiness as a side effect. Does the evidence suggest that a lower proportion of subjects in group 1 experienced drowsiness as a side </p><p> effect than subjects in group 2 at the level of significance?</p><p>(a) Setup</p><p>(b) value</p><p>(c) Conclusion</p><p>Example 2: The body mass index (BMI) of an individual is one measure that is used to judge whether an individual is overweight or not. A BMI between 20 and 25 indicates that one is at a normal weight. In a survey of 750 men and 750 women, the Gallup organization found that 203 men and 270 women were normal weight. Construct a 90% confidence interval to gauge whether there is a difference in the proportion of men and women who are normal weight. Interpret the interval. Ch 11.2 Inference about Two Means: Dependent Samples</p><p>Objective A : Test Hypotheses or Confidence Intervals about the Population Mean Difference of Matched-Pairs Data</p><p>Example 1: In an experiment conducted online at the University of Mississippi, study </p><p> participants are asked to react to a stimulus. In one experiment, the participant must press a key on seeing a blue screen. Reaction time (in seconds_ to press the key is measured. The same person is then asked to press a key on seeing a red screen, again with reaction time measured. The results for six randomly sampled study participants are as follows:</p><p>(a) Why are these matched-pairs data?</p><p>(b) Is the reaction time to the blue stimulus different from the reaction time to the red stimulus at the level of significance? Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers. (c) Construct a 99% confidence interval about the population mean difference. Interpret your results.</p><p>Ch 11.3 Inference about Two Means: Independent Samples</p><p>Objective A : Test Hypotheses or Confidence Intervals regarding the Difference of Two Independent Means Example 1: Example 2: Ch 11.4 Inference about Two Population Standard Deviations</p><p>Objective A : Fisher’s distribution Objective B : Test Hypotheses regarding Two Population Standard Deviations</p><p>Example 1: Assume that the populations are normally distributed.</p><p>Example 2:</p>