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To determine which facility increased their efficiency more during that hour, we can calculate the z-scores for each facility based on their mean and standard deviation.
For the water bottling facility:
z = (X - μ) / σ
where X = 35.6, μ = 34.1, and σ = 2.13
z = (35.6 - 34.1) / 2.13
z = 0.70
For the cola bottling facility:
z = (X - μ) / σ
where X = 26.4, μ = 25.7, and σ = 1.63
z = (26.4 - 25.7) / 1.63
z = 0.43
Since the z-score for the water bottling facility is higher than the z-score for the cola bottling facility, the water bottling facility increased their efficiency more during that hour.