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Finding the Fourth Proportional to 687.30, 948.48 and 392.61

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Solution

The fourth proportional to 687.30, 948.48 and 392.61 is: 541.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.30 : 948.48 = 392.61 : x
  2. Step 2: Convert to fraction form
    687.30/948.48 = 392.61/x
  3. Step 3: Cross multiply
    687.30x = 948.48 × 392.61
  4. Step 4: Simplify right side
    687.30x = 372,382.73
  5. Step 5: Solve for x
    x = 372,382.73/687.30
  6. Step 6: Final answer
    x = 541.81

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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.