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Finding the Fourth Proportional to 708.86, 978.21 and 394.12

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Solution

The fourth proportional to 708.86, 978.21 and 394.12 is: 543.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.86 : 978.21 = 394.12 : x
  2. Step 2: Convert to fraction form
    708.86/978.21 = 394.12/x
  3. Step 3: Cross multiply
    708.86x = 978.21 × 394.12
  4. Step 4: Simplify right side
    708.86x = 385,532.13
  5. Step 5: Solve for x
    x = 385,532.13/708.86
  6. Step 6: Final answer
    x = 543.88

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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.