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Finding the Fourth Proportional to 391.32, 539.75 and 256.77

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Solution

The fourth proportional to 391.32, 539.75 and 256.77 is: 354.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.32 : 539.75 = 256.77 : x
  2. Step 2: Convert to fraction form
    391.32/539.75 = 256.77/x
  3. Step 3: Cross multiply
    391.32x = 539.75 × 256.77
  4. Step 4: Simplify right side
    391.32x = 138,592.25
  5. Step 5: Solve for x
    x = 138,592.25/391.32
  6. Step 6: Final answer
    x = 354.17

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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.