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Finding the Fourth Proportional to 256.60, 353.78 and 209.92

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Solution

The fourth proportional to 256.60, 353.78 and 209.92 is: 289.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.60 : 353.78 = 209.92 : x
  2. Step 2: Convert to fraction form
    256.60/353.78 = 209.92/x
  3. Step 3: Cross multiply
    256.60x = 353.78 × 209.92
  4. Step 4: Simplify right side
    256.60x = 74,265.50
  5. Step 5: Solve for x
    x = 74,265.50/256.60
  6. Step 6: Final answer
    x = 289.42

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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.