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Finding the Fourth Proportional to 392.84, 542.40 and 288.12

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Solution

The fourth proportional to 392.84, 542.40 and 288.12 is: 397.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.84 : 542.40 = 288.12 : x
  2. Step 2: Convert to fraction form
    392.84/542.40 = 288.12/x
  3. Step 3: Cross multiply
    392.84x = 542.40 × 288.12
  4. Step 4: Simplify right side
    392.84x = 156,276.29
  5. Step 5: Solve for x
    x = 156,276.29/392.84
  6. Step 6: Final answer
    x = 397.81

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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.