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Finding the Fourth Proportional to 392.82, 542.58 and 287.75

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Solution

The fourth proportional to 392.82, 542.58 and 287.75 is: 397.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.82 : 542.58 = 287.75 : x
  2. Step 2: Convert to fraction form
    392.82/542.58 = 287.75/x
  3. Step 3: Cross multiply
    392.82x = 542.58 × 287.75
  4. Step 4: Simplify right side
    392.82x = 156,123.96
  5. Step 5: Solve for x
    x = 156,123.96/392.82
  6. Step 6: Final answer
    x = 397.44

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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.