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Finding the Fourth Proportional to 256.28, 353.28 and 189.78

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Solution

The fourth proportional to 256.28, 353.28 and 189.78 is: 261.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.28 : 353.28 = 189.78 : x
  2. Step 2: Convert to fraction form
    256.28/353.28 = 189.78/x
  3. Step 3: Cross multiply
    256.28x = 353.28 × 189.78
  4. Step 4: Simplify right side
    256.28x = 67,045.48
  5. Step 5: Solve for x
    x = 67,045.48/256.28
  6. Step 6: Final answer
    x = 261.61

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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.