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Finding the Fourth Proportional to 687, 948.18 and 392.28

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Solution

The fourth proportional to 687, 948.18 and 392.28 is: 541.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    687 : 948.18 = 392.28 : x
  2. Step 2: Convert to fraction form
    687/948.18 = 392.28/x
  3. Step 3: Cross multiply
    687x = 948.18 × 392.28
  4. Step 4: Simplify right side
    687x = 371,952.05
  5. Step 5: Solve for x
    x = 371,952.05/687
  6. Step 6: Final answer
    x = 541.41

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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.