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Finding the Fourth Proportional to 645.54, 890.85 and 383.78

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Solution

The fourth proportional to 645.54, 890.85 and 383.78 is: 529.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.54 : 890.85 = 383.78 : x
  2. Step 2: Convert to fraction form
    645.54/890.85 = 383.78/x
  3. Step 3: Cross multiply
    645.54x = 890.85 × 383.78
  4. Step 4: Simplify right side
    645.54x = 341,890.41
  5. Step 5: Solve for x
    x = 341,890.41/645.54
  6. Step 6: Final answer
    x = 529.62

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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.