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Finding the Fourth Proportional to 644.34, 888.90 and 520.40

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Solution

The fourth proportional to 644.34, 888.90 and 520.40 is: 717.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.34 : 888.90 = 520.40 : x
  2. Step 2: Convert to fraction form
    644.34/888.90 = 520.40/x
  3. Step 3: Cross multiply
    644.34x = 888.90 × 520.40
  4. Step 4: Simplify right side
    644.34x = 462,583.56
  5. Step 5: Solve for x
    x = 462,583.56/644.34
  6. Step 6: Final answer
    x = 717.92

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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.