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When Michael commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 24 minutes and a standard deviation of 3 minutes. Out of the 273 days that Michael commutes to work per year, how many times would his commute be between 19 and 31 minutes, to the nearest whole number?

When Michael commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 2424 minutes and a standard deviation of 33 minutes. Out of the 273273 days that Michael commutes to work per year, how many times would his commute be between 1919 and 3131 minutes, to the nearest whole number?

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Q. When Michael commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 2424 minutes and a standard deviation of 33 minutes. Out of the 273273 days that Michael commutes to work per year, how many times would his commute be between 1919 and 3131 minutes, to the nearest whole number?
  1. Identify Parameters: Identify the parameters of the normal distribution. The mean (μ\mu) is 2424 minutes, and the standard deviation (σ\sigma) is 33 minutes.
  2. Convert to Z-scores: Convert the commute time range to z-scores.\newlineTo find the z-score for 1919 minutes: z=Xμσ=19243=531.67 z = \frac{X - \mu}{\sigma} = \frac{19 - 24}{3} = \frac{-5}{3} \approx -1.67 \newlineTo find the z-score for 3131 minutes: z=Xμσ=31243=732.33 z = \frac{X - \mu}{\sigma} = \frac{31 - 24}{3} = \frac{7}{3} \approx 2.33
  3. Use Normal Distribution Table: Use the standard normal distribution table to find the probabilities corresponding to the z-scores.\newlineThe probability of a z-score being less than 1.67-1.67 is approximately 0.04750.0475.\newlineThe probability of a z-score being less than 2.332.33 is approximately 0.99010.9901.
  4. Calculate Probability Range: Calculate the probability of the commute time being between 1919 and 3131 minutes.\newlineSubtract the probability of the commute being less than 1919 minutes from the probability of the commute being less than 3131 minutes.\newlineProbability between 1919 and 3131 minutes = 0.99010.0475=0.94260.9901 - 0.0475 = 0.9426
  5. Calculate Number of Days: Calculate the number of days Michael's commute would be between 1919 and 3131 minutes.\newlineMultiply the total number of commuting days by the probability found in Step 44.\newlineNumber of days = 273×0.9426257.4273 \times 0.9426 \approx 257.4
  6. Round to Nearest Whole Number: Round the result to the nearest whole number.\newlineThe number of days Michael's commute would be between 1919 and 3131 minutes is approximately 257257 days when rounded to the nearest whole number.

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