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Finding the Fourth Proportional to 256.61, 384.78 and 102.57

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Solution

The fourth proportional to 256.61, 384.78 and 102.57 is: 153.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.61 : 384.78 = 102.57 : x
  2. Step 2: Convert to fraction form
    256.61/384.78 = 102.57/x
  3. Step 3: Cross multiply
    256.61x = 384.78 × 102.57
  4. Step 4: Simplify right side
    256.61x = 39,466.88
  5. Step 5: Solve for x
    x = 39,466.88/256.61
  6. Step 6: Final answer
    x = 153.80

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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.