Final answer:
The second group will hike a total of 9 miles.
Step-by-step explanation:
To find the total miles the second group will hike, we need to add up the distances of the three trails they hike.
The Alpine Trail is hiked 1 time, so we add 0 miles.
The Cedar Trail is hiked 2 times, so we add 2 times the distance of the Cedar Trail.
The Date Trail is hiked 2 times, so we add 2 times the distance of the Date Trail.
The Cedar Trail is hiked 2 times, so we add 2 * 0 miles = 0 miles.
The Date Trail is 4.5 miles long, so we add 2 * 4.5 miles = 9 miles.
The total miles hiked by the second group is 0 miles + 9 miles = 9 miles.