This problem is an example of ratio and proportion. A ratio is a comparison between two different things. You are given the time of about 26.1 seconds to fold 1 shirt. Also you are given 48 shirts. You are required to find the time in seconds to fold 48 shirts. The solution of this problem is,
26.1 seconds /1 shirt = time/ 48 shirts
time = (48 shirts) (26.1 seconds /1 shirt)
time = 1,252.8 seconds
The time it takes to fold 48 shirts is 1,252.8 seconds.