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Finding the Fourth Proportional to 256.15, 353.17 and 209.42

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Solution

The fourth proportional to 256.15, 353.17 and 209.42 is: 288.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.15 : 353.17 = 209.42 : x
  2. Step 2: Convert to fraction form
    256.15/353.17 = 209.42/x
  3. Step 3: Cross multiply
    256.15x = 353.17 × 209.42
  4. Step 4: Simplify right side
    256.15x = 73,958.91
  5. Step 5: Solve for x
    x = 73,958.91/256.15
  6. Step 6: Final answer
    x = 288.74

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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.