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Finding the Fourth Proportional to 687.31, 948.28 and 392.56

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Solution

The fourth proportional to 687.31, 948.28 and 392.56 is: 541.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.31 : 948.28 = 392.56 : x
  2. Step 2: Convert to fraction form
    687.31/948.28 = 392.56/x
  3. Step 3: Cross multiply
    687.31x = 948.28 × 392.56
  4. Step 4: Simplify right side
    687.31x = 372,256.80
  5. Step 5: Solve for x
    x = 372,256.80/687.31
  6. Step 6: Final answer
    x = 541.61

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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.