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Finding the Fourth Proportional to 709.05, 978.50 and 398.55

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Solution

The fourth proportional to 709.05, 978.50 and 398.55 is: 550.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.05 : 978.50 = 398.55 : x
  2. Step 2: Convert to fraction form
    709.05/978.50 = 398.55/x
  3. Step 3: Cross multiply
    709.05x = 978.50 × 398.55
  4. Step 4: Simplify right side
    709.05x = 389,979.18
  5. Step 5: Solve for x
    x = 389,979.18/709.05
  6. Step 6: Final answer
    x = 550.00

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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.