D) You should expect the next randomly chosen male to have 1.71 piercings
Here's how we arrive at this answer:
1. First, we need to understand the hypothesis. It is suggesting that there might be a relationship between Gender (the independent variable) and Piercings (the dependent variable) among students in this study.
2. To test this hypothesis, we need to fit a Regression model to our data. The formula 'Piercings ~ Gender' is used for this purpose. What this formula does is to model the number of Piercings as a function of Gender.
3. After fitting the model, we create a function that would take this model and a gender (in our case 'M' for males) as inputs. This function is used for making predictions about the number of piercings a student of that gender would have.
4. Once we pass our model and 'M' to our function, it returns a prediction. According to the given information, the output is 1.71.
5. What this output actually means is that if we randomly select a male student from our data, we can expect him to have around 1.71 piercings. Of course, this is a statistical expectation and actual number of piercings can vary.