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Finding the Fourth Proportional to 708.81, 978.11 and 394.05

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Solution

The fourth proportional to 708.81, 978.11 and 394.05 is: 543.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.81 : 978.11 = 394.05 : x
  2. Step 2: Convert to fraction form
    708.81/978.11 = 394.05/x
  3. Step 3: Cross multiply
    708.81x = 978.11 × 394.05
  4. Step 4: Simplify right side
    708.81x = 385,421.92
  5. Step 5: Solve for x
    x = 385,421.92/708.81
  6. Step 6: Final answer
    x = 543.76

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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.