Answer:
To find Sasha's elevation at the fourth rest station, we need to calculate the distance she has descended. Since she takes a break at the rest stations every 23 of a mile, we can calculate her descent as follows:
Distance descended = 4 rest stations * 23 of a mile per rest station = 4 * 23 = 92 of a mile
Since she started at sea level, we can say that for every mile she descends, her elevation drops by 1, so for 92 of a mile, her elevation would drop by:
92 * 1/1 = 92 units
So, Sasha's elevation now is 92 units lower than sea level.
Explanation: