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Finding the Fourth Proportional to 396.09, 545.40 and 285.35

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Solution

The fourth proportional to 396.09, 545.40 and 285.35 is: 392.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    396.09 : 545.40 = 285.35 : x
  2. Step 2: Convert to fraction form
    396.09/545.40 = 285.35/x
  3. Step 3: Cross multiply
    396.09x = 545.40 × 285.35
  4. Step 4: Simplify right side
    396.09x = 155,627.16
  5. Step 5: Solve for x
    x = 155,627.16/396.09
  6. Step 6: Final answer
    x = 392.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.