Final answer:
The situations that could have a regression line with a positive slope are: the cumulative number of ships launched by ship builders as a function of months, the number of cars produced as a function of days since the last strike, and the number of backorders as a function of assembly workers.
Step-by-step explanation:
A regression line with a positive slope indicates a positive relationship between two variables, meaning that when one variable increases, the other variable also increases. Based on the given situations, the data sets or plots that could have a regression line with a positive slope are:
- The cumulative number of ships launched by ship builders as a function of the number of months since the start of the year. This implies that as time increases, the number of ships launched increases.
- The number of cars produced as a function of the number of days since the end of the last strike. This suggests that as time progresses, the production of cars increases.
- The number of backorders as a function of the number of assembly workers in a manufacturing company that makes the product. This indicates that as the number of assembly workers increases, the number of backorders also increases.