Lori is driving from her home to a conference 320 miles away. The table below provides the total distance traveled at specific times since the trip began. Use the table to estimate the average rate of change in distance (average speed) as t varies from hour 1 to hour 4 of the trip. Express the answer as a decimal accurate to two decimal places. time since trip began (hours) distance traveled (miles) 1 70 2 125 3 167 4 232 302