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Finding the Fourth Proportional to 687.80, 948.93 and 392.85

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Solution

The fourth proportional to 687.80, 948.93 and 392.85 is: 542.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.80 : 948.93 = 392.85 : x
  2. Step 2: Convert to fraction form
    687.80/948.93 = 392.85/x
  3. Step 3: Cross multiply
    687.80x = 948.93 × 392.85
  4. Step 4: Simplify right side
    687.80x = 372,787.15
  5. Step 5: Solve for x
    x = 372,787.15/687.80
  6. Step 6: Final answer
    x = 542.00

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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.