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Finding the Fourth Proportional to 613.80, 847.28 and 392.87

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Solution

The fourth proportional to 613.80, 847.28 and 392.87 is: 542.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.80 : 847.28 = 392.87 : x
  2. Step 2: Convert to fraction form
    613.80/847.28 = 392.87/x
  3. Step 3: Cross multiply
    613.80x = 847.28 × 392.87
  4. Step 4: Simplify right side
    613.80x = 332,864.69
  5. Step 5: Solve for x
    x = 332,864.69/613.80
  6. Step 6: Final answer
    x = 542.31

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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.