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Finding the Fourth Proportional to 647.87, 971.69 and 209.12

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Solution

The fourth proportional to 647.87, 971.69 and 209.12 is: 313.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.87 : 971.69 = 209.12 : x
  2. Step 2: Convert to fraction form
    647.87/971.69 = 209.12/x
  3. Step 3: Cross multiply
    647.87x = 971.69 × 209.12
  4. Step 4: Simplify right side
    647.87x = 203,193.91
  5. Step 5: Solve for x
    x = 203,193.91/647.87
  6. Step 6: Final answer
    x = 313.64

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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.