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Finding the Fourth Proportional to 709.56, 978.78 and 488.13

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Solution

The fourth proportional to 709.56, 978.78 and 488.13 is: 673.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.56 : 978.78 = 488.13 : x
  2. Step 2: Convert to fraction form
    709.56/978.78 = 488.13/x
  3. Step 3: Cross multiply
    709.56x = 978.78 × 488.13
  4. Step 4: Simplify right side
    709.56x = 477,771.88
  5. Step 5: Solve for x
    x = 477,771.88/709.56
  6. Step 6: Final answer
    x = 673.34

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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.