A scatter plot is linear fitting of the data points. This is done by linear regression. A linear relationship is created from the data points as shown in the graph. Generally, this line would dictate the relationship between the variable for all ranges. When t = 6 hours, just find 6 in the x-axis and trace upward until you reach the line. Then, move to the left until you reach the y-axis. Read off the value. For 6 hours, it would be 55 mistakes. The answer is A.
