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Finding the Fourth Proportional to 279.20, 385.40 and 168.72

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Solution

The fourth proportional to 279.20, 385.40 and 168.72 is: 232.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.20 : 385.40 = 168.72 : x
  2. Step 2: Convert to fraction form
    279.20/385.40 = 168.72/x
  3. Step 3: Cross multiply
    279.20x = 385.40 × 168.72
  4. Step 4: Simplify right side
    279.20x = 65,024.69
  5. Step 5: Solve for x
    x = 65,024.69/279.20
  6. Step 6: Final answer
    x = 232.90

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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.