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Finding the Fourth Proportional to 648.56, 972.90 and 209.70

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Solution

The fourth proportional to 648.56, 972.90 and 209.70 is: 314.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.56 : 972.90 = 209.70 : x
  2. Step 2: Convert to fraction form
    648.56/972.90 = 209.70/x
  3. Step 3: Cross multiply
    648.56x = 972.90 × 209.70
  4. Step 4: Simplify right side
    648.56x = 204,011.22
  5. Step 5: Solve for x
    x = 204,011.22/648.56
  6. Step 6: Final answer
    x = 314.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.