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Finding the Fourth Proportional to 256.75, 385.05 and 74.09

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Solution

The fourth proportional to 256.75, 385.05 and 74.09 is: 111.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.75 : 385.05 = 74.09 : x
  2. Step 2: Convert to fraction form
    256.75/385.05 = 74.09/x
  3. Step 3: Cross multiply
    256.75x = 385.05 × 74.09
  4. Step 4: Simplify right side
    256.75x = 28,529.59
  5. Step 5: Solve for x
    x = 28,529.59/256.75
  6. Step 6: Final answer
    x = 111.12

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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.