The z-score is calculated as (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.
For $1,320, the z-score is (1320 - 1560) / 240 = -1.
For $1,800, the z-score is (1800 - 1560) / 240 = 1.
Looking up these z-scores in the z-table,
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