The marble was traveling at 4.05 miles per hour.
Since in science class, Antonio and Anna were measuring the approximate speed of a marble as it exits from an 8-foot-long ramp, and they discovered that it took 2.1 seconds for the marble to travel 12.5 feet from the end of the ramp, to determine approximately how fast was the marble traveling as it exited from the ramp to the nearest hundredth of a second, the following calculation must be performed:
Therefore, the marble was traveling at 4.05 miles per hour.
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