Final answer:
The percent decrease in the average waiting time in line is approximately 35.71%.
Step-by-step explanation:
To find the percent decrease in the average amount of time a customer waits in line, we can use the formula:
Percent Decrease = (Initial Value - Final Value) / Initial Value * 100
Substituting the given values:
Percent Decrease = (4.2 - 2.7) / 4.2 * 100 = 35.71%
Therefore, the percent decrease is approximately 35.71%.
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