Josette bought 3 bottles of mineral water for €1.50. How much will four bottles cost? Let's answer step by step:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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A bottle costs 1.50 € / 3 = 0.50 €. So, four bottles cost 0.50 € * 4 = 2 €. The answer: 2.