Solving for Chi-Square Test of goodness of fit.pptx

Solving for Chi-Square Test of goodness of fit

1. Example 1: Out of 600 throws in a Scissors-Paper-Rock competition there were 235 rocks, 194 scissors, and 171 papers thrown. Is there evidence a “weapon” preference (at the 5% level of sig)? Observed Expected Rock 235 Paper 194 Scissor 171

2. Example 2: In the 2000 US Census, the ages of individuals in a small town were found to be the following: Less than 18 18 - 35 Greater than 35 20% 30% 50% In 2010, the ages of n = 500 individuals were sampled. Below are the results: Less than 18 18 - 35 Greater than 35 121 288 91 Using alpha = 0.05, would you conclude that the population distribution of ages has changed in the last 10 years?

3. Example 1: A study is being conducted to determine whether there is a relationship between jogging and blood pressure. A random sample of 210 subjects is selected, and they are classified as shown in the contingency table. Using 0.05, determine whether a relationship exist between jogging and blood pressure. Blood Pressure Jogging Status LOW MODERATE HIGH Jogger 34 57 21 Non-jogger 15 63 20

4. Example 2: Dr. Meerse wanted to investigate whether the gender and preferred color of the shirt were independent. This means that she tried to find out if a person’s gender influences their color choice. She conducted a survey and organized her data in the following table. Black White Red Blue Male 48 12 33 57 Female 34 46 42 26

5. Example 3: The table below shows the average number of hours students spend studying for classes each day in a high school. Is the average number of hours dependent on the type of students? (use a 5% significance level) 0-2 Hrs 2-4 Hrs 4-6 Hrs Freshmen 76 143 91 Seniors 147 109 64