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Finding the Fourth Proportional to 709.78, 979.40 and 395.02

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Solution

The fourth proportional to 709.78, 979.40 and 395.02 is: 545.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.78 : 979.40 = 395.02 : x
  2. Step 2: Convert to fraction form
    709.78/979.40 = 395.02/x
  3. Step 3: Cross multiply
    709.78x = 979.40 × 395.02
  4. Step 4: Simplify right side
    709.78x = 386,882.59
  5. Step 5: Solve for x
    x = 386,882.59/709.78
  6. Step 6: Final answer
    x = 545.07

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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.