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Finding the Fourth Proportional to 709.14, 978.40 and 512.90

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Solution

The fourth proportional to 709.14, 978.40 and 512.90 is: 707.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.14 : 978.40 = 512.90 : x
  2. Step 2: Convert to fraction form
    709.14/978.40 = 512.90/x
  3. Step 3: Cross multiply
    709.14x = 978.40 × 512.90
  4. Step 4: Simplify right side
    709.14x = 501,821.36
  5. Step 5: Solve for x
    x = 501,821.36/709.14
  6. Step 6: Final answer
    x = 707.65

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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.