The data table matches 6.9 s with 2.0 gallons. This is one individual measurement. The water seems to have been flowing at a steady rate as evidenced by the linear nature of the graph. Thus a much more accurate value for the amount that had flowed after a given time would come from the line of best fit.

The line of best fit clearly goes above the 6.9-s data point so somewhat more than 2.0 gallons had probably flowed by this time. The actual value would require estimation since we're reading a graph, but the correct answer is clearly more than 2.0 gallons.