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Finding the Fourth Proportional to 645.85, 891.32 and 383.83

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Solution

The fourth proportional to 645.85, 891.32 and 383.83 is: 529.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.85 : 891.32 = 383.83 : x
  2. Step 2: Convert to fraction form
    645.85/891.32 = 383.83/x
  3. Step 3: Cross multiply
    645.85x = 891.32 × 383.83
  4. Step 4: Simplify right side
    645.85x = 342,113.44
  5. Step 5: Solve for x
    x = 342,113.44/645.85
  6. Step 6: Final answer
    x = 529.71

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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.