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Finding the Fourth Proportional to 648.57, 972.72 and 209.86

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Solution

The fourth proportional to 648.57, 972.72 and 209.86 is: 314.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.57 : 972.72 = 209.86 : x
  2. Step 2: Convert to fraction form
    648.57/972.72 = 209.86/x
  3. Step 3: Cross multiply
    648.57x = 972.72 × 209.86
  4. Step 4: Simplify right side
    648.57x = 204,137.45
  5. Step 5: Solve for x
    x = 204,137.45/648.57
  6. Step 6: Final answer
    x = 314.75

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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.