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Finding the Fourth Proportional to 709.09, 978.11 and 498.89

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Solution

The fourth proportional to 709.09, 978.11 and 498.89 is: 688.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.09 : 978.11 = 498.89 : x
  2. Step 2: Convert to fraction form
    709.09/978.11 = 498.89/x
  3. Step 3: Cross multiply
    709.09x = 978.11 × 498.89
  4. Step 4: Simplify right side
    709.09x = 487,971.12
  5. Step 5: Solve for x
    x = 487,971.12/709.09
  6. Step 6: Final answer
    x = 688.17

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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.