Question 6 • Probability and Statistics with Applications Honors Sem-2-FL-1210300 (2024-2025)
For a sample of 100 batches, the standard deviation of the sample mean is 1.9/√100 = 0.19 minutes. A mean of 6.5 minutes is (6.5 − 6)/0.19 ≈ 2.63 standard deviations above the population mean. The probability of being above that z-score is about 0.0042, so the correct choice is 0.0042.
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