Let's analyze the problem step by step:
1. Population and Sample:
- Population: In this context, the population refers to the entire group of individuals Bart is interested in studying. Since Bart wants to know the sandwich preferences of his customers, the population consists of all customers who eat at the food truck.
- Sample: A sample is a subset of the population that Bart actually surveys to draw conclusions. Here, Bart surveyed a few of his friends who have eaten at his food truck. Therefore, the sample consists of friends who have eaten at the food truck and were surveyed.
2. Conclusion Based on Survey Results:
- For the given survey, the number of friends preferring grilled sandwiches is 15, whereas those preferring plain sandwiches is 5. Based on this data, it can be concluded that within the sample, the preference is for grilled sandwiches. Hence, the sample prefers grilled sandwiches.
3. Accuracy Improvement:
- To obtain more accurate and generalizable results, Bart should survey a more representative group of his entire customer base. In this scenario, more accurate results would have been obtained if Bart had surveyed a random sample of all customers who visit the food truck, rather than just his friends.
Putting it all together:
In this case, the population consists of all customers who eat at the food truck and the sample consists of friends who have eaten at the food truck and were surveyed. Based on the results, it can be concluded that the sample prefers grilled sandwiches. The results would have been more accurate if Bart had surveyed a random sample of all customers.
