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Finding the Fourth Proportional to 709.14, 978.60 and 394.40

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Solution

The fourth proportional to 709.14, 978.60 and 394.40 is: 544.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.14 : 978.60 = 394.40 : x
  2. Step 2: Convert to fraction form
    709.14/978.60 = 394.40/x
  3. Step 3: Cross multiply
    709.14x = 978.60 × 394.40
  4. Step 4: Simplify right side
    709.14x = 385,959.84
  5. Step 5: Solve for x
    x = 385,959.84/709.14
  6. Step 6: Final answer
    x = 544.26

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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.