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Finding the Fourth Proportional to 708.20, 977.28 and 397.72

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Solution

The fourth proportional to 708.20, 977.28 and 397.72 is: 548.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.20 : 977.28 = 397.72 : x
  2. Step 2: Convert to fraction form
    708.20/977.28 = 397.72/x
  3. Step 3: Cross multiply
    708.20x = 977.28 × 397.72
  4. Step 4: Simplify right side
    708.20x = 388,683.80
  5. Step 5: Solve for x
    x = 388,683.80/708.20
  6. Step 6: Final answer
    x = 548.83

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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.