Final answer:
The slope, representing the rate of change in the test score related to the number of questions answered incorrectly, is found to be -10. This means for every additional question answered incorrectly, there is a 10 point decrease in the score. It is considered a negative slope.
Step-by-step explanation:
If we're looking at the relationship between the number of incorrectly answered questions and the test score, we can calculate the slope by taking two points on the line that represents this relationship. The first point could be (1, 90) where 1 represents one question answered incorrectly and 90 the corresponding test score. The second point could be (5, 50), where 5 represents five questions incorrect and 50 the corresponding test score.
To find the slope, we use the formula: slope = (change in y) / (change in x). Here, the change in y is 50-90 = -40 and the change in x is 5-1 = 4. This gives us a slope of -40/4 = -10.
This slope means that for each additional question answered incorrectly, the test score decreases by 10 points. Therefore, it is a negative slope.