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Finding the Fourth Proportional to 709.30, 978.78 and 394.53

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Solution

The fourth proportional to 709.30, 978.78 and 394.53 is: 544.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.30 : 978.78 = 394.53 : x
  2. Step 2: Convert to fraction form
    709.30/978.78 = 394.53/x
  3. Step 3: Cross multiply
    709.30x = 978.78 × 394.53
  4. Step 4: Simplify right side
    709.30x = 386,158.07
  5. Step 5: Solve for x
    x = 386,158.07/709.30
  6. Step 6: Final answer
    x = 544.42

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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.