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Finding the Fourth Proportional to 256.43, 384.59 and 91.87

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Solution

The fourth proportional to 256.43, 384.59 and 91.87 is: 137.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.43 : 384.59 = 91.87 : x
  2. Step 2: Convert to fraction form
    256.43/384.59 = 91.87/x
  3. Step 3: Cross multiply
    256.43x = 384.59 × 91.87
  4. Step 4: Simplify right side
    256.43x = 35,331.55
  5. Step 5: Solve for x
    x = 35,331.55/256.43
  6. Step 6: Final answer
    x = 137.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.