The answer is an average rate of change of 110 more dollars in her account per week. You find this by first subtracting the starting amount of 250 from the end amount of 800 that equals 550. then you divide that number by five, the number of weeks, to get the average rate of change.
Absolute value is the magnitude of a number without regard to its sign. for example, the absolute value of 5 is 5, and the absolute value of -5 is also 5!