An ideal gas is enclosed within a container with a movable piston as the lid. The gas is initially at a pressure of 3 atmospheres and occupies a volume of 2 liters. The piston is lowered so that the gas now occupies 1.5 liters at a pressure of \(P\). If the process was carried out slowly, maintaining constant temperature in contact with a suitable reservoir, what is \(P\) in atmospheres?
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