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Finding the Fourth Proportional to 645.34, 890.62 and 396.64

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Solution

The fourth proportional to 645.34, 890.62 and 396.64 is: 547.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.34 : 890.62 = 396.64 : x
  2. Step 2: Convert to fraction form
    645.34/890.62 = 396.64/x
  3. Step 3: Cross multiply
    645.34x = 890.62 × 396.64
  4. Step 4: Simplify right side
    645.34x = 353,255.52
  5. Step 5: Solve for x
    x = 353,255.52/645.34
  6. Step 6: Final answer
    x = 547.39

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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.