give me examples on PPDAC in statistical analysis and give me 3 examples

PPDAC is a framework used in statistical analysis, standing for Problem, Plan, Data, Analysis, and Conclusion. Here are three examples to illustrate this method: ### Example 1: Examining the Effect of Study Hours on Exam Scores 1. **Problem**: Does the number of hours a student studies affect their exam scores? 2. **Plan**: - Define a hypothesis that increased study hours lead to higher exam scores. - Decide to collect data from a random sample of students across several courses. - Determine variables: independent variable (study hours) and dependent variable (exam scores). 3. **Data**: - Collect data from a survey of 100 students about their study habits and their scores on the most recent exam. 4. **Analysis**: - Use statistical methods such as correlation analysis to determine the relationship between study hours and exam scores. Additionally, run a regression analysis to quantify the impact of study hours on scores. 5. **Conclusion**: - Interpret the results to either support or reject the hypothesis. For example, if it’s found that there is a significant positive correlation, one might conclude that more study hours generally lead to better exam performance. --- ### Example 2: Analyzing Customer Satisfaction for a Product 1. **Problem**: What factors contribute to customer satisfaction for a new product? 2. **Plan**: - Identify factors such as product quality, customer service, and price as variables influencing satisfaction. - Plan to conduct a survey aimed at customers who recently purchased the product. 3. **Data**: - Collect data from 200 customers using a structured questionnaire that includes Likert scale questions regarding various satisfaction factors. 4. **Analysis**: - Perform factor analysis to identify which variables most strongly correlate with overall satisfaction. Use descriptive statistics to summarize responses and inferential statistics to estimate confidence intervals. 5. **Conclusion**: - Determine which factors are most critical in affecting customer satisfaction, such as if product quality significantly outscored the others, thus guiding future product improvements. --- ### Example 3: Investigating Trends in Air Quality Over Time 1. **Problem**: Has air quality improved or worsened in a certain region over the past decade? 2. **Plan**: - Formulate a hypothesis that air quality has improved due to new environmental regulations. - Decide to analyze air quality index (AQI) data collected annually over the last ten years. 3. **Data**: - Acquire yearly AQI data from government databases for the region of interest. 4. **Analysis**: - Utilize time series analysis to evaluate trends in the AQI data. Apply statistical tests such as the Mann-Kendall trend test to assess whether changes are statistically significant over time. 5. **Conclusion**: - Based on the analysis, draw conclusions about the trend in air quality. If the data shows a significant decrease in AQI scores, one might conclude that air quality has indeed improved over the decade. --- These examples illustrate how the PPDAC framework can be applied to structure a statistical analysis, helping to clarify the research process from identifying a problem to drawing meaningful conclusions based on data.