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Finding the Fourth Proportional to 687.82, 948.99 and 392.98

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Solution

The fourth proportional to 687.82, 948.99 and 392.98 is: 542.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.82 : 948.99 = 392.98 : x
  2. Step 2: Convert to fraction form
    687.82/948.99 = 392.98/x
  3. Step 3: Cross multiply
    687.82x = 948.99 × 392.98
  4. Step 4: Simplify right side
    687.82x = 372,934.09
  5. Step 5: Solve for x
    x = 372,934.09/687.82
  6. Step 6: Final answer
    x = 542.20

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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.