This scatterplot shows the performance of a thermocouple using the variables temperature difference and voltage. Select the answer choice that accurately describes the data's form, direction, and strength in the scatterplot.
1. Form: Linear, Direction: Positive, Strength: Strong
2. Form: Non-linear, Direction: Negative, Strength: Weak
3. Form: No apparent pattern, Direction: Random, Strength: None
4. Form: Exponential, Direction: Positive, Strength: Moderate
