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Complete the statement. Round your answer to the nearest thousandth.\newlineIn a population that is normally distributed with mean 4747 and standard deviation 1313, the bottom 90%90\% of the values are those less than ___.

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Q. Complete the statement. Round your answer to the nearest thousandth.\newlineIn a population that is normally distributed with mean 4747 and standard deviation 1313, the bottom 90%90\% of the values are those less than ___.
  1. Find z-score for 9090%: Find the z-score for 9090\%. Using a z-table or calculator, the z-score for 9090\% is approximately 1.2821.282.
  2. Use z-score formula: Use the z-score formula to solve for XX.
    mean (μ\mu): 4747
    standard deviation (σ\sigma): 1313
    z-score (ZZ): 1.2821.282
    Z=XμσZ = \frac{X - \mu}{\sigma}
    1.282=X47131.282 = \frac{X - 47}{13}
  3. Multiply by standard deviation: Multiply both sides by the standard deviation.\newline1.282×13=X471.282 \times 13 = X - 47\newline16.666=X4716.666 = X - 47
  4. Add mean to solve for X: Add the mean to both sides to solve for X.\newlineX=16.666+47X = 16.666 + 47\newlineX=63.666X = 63.666

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