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Finding the Fourth Proportional to 279.76, 420.39 and 238.76

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Solution

The fourth proportional to 279.76, 420.39 and 238.76 is: 358.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.76 : 420.39 = 238.76 : x
  2. Step 2: Convert to fraction form
    279.76/420.39 = 238.76/x
  3. Step 3: Cross multiply
    279.76x = 420.39 × 238.76
  4. Step 4: Simplify right side
    279.76x = 100,372.32
  5. Step 5: Solve for x
    x = 100,372.32/279.76
  6. Step 6: Final answer
    x = 358.78

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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.