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Finding the Fourth Proportional to 687.10, 948.22 and 392.31

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Solution

The fourth proportional to 687.10, 948.22 and 392.31 is: 541.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.10 : 948.22 = 392.31 : x
  2. Step 2: Convert to fraction form
    687.10/948.22 = 392.31/x
  3. Step 3: Cross multiply
    687.10x = 948.22 × 392.31
  4. Step 4: Simplify right side
    687.10x = 371,991.45
  5. Step 5: Solve for x
    x = 371,991.45/687.10
  6. Step 6: Final answer
    x = 541.40

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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.