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Finding the Fourth Proportional to 451.20, 676.80 and 258.78

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Solution

The fourth proportional to 451.20, 676.80 and 258.78 is: 388.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.20 : 676.80 = 258.78 : x
  2. Step 2: Convert to fraction form
    451.20/676.80 = 258.78/x
  3. Step 3: Cross multiply
    451.20x = 676.80 × 258.78
  4. Step 4: Simplify right side
    451.20x = 175,142.30
  5. Step 5: Solve for x
    x = 175,142.30/451.20
  6. Step 6: Final answer
    x = 388.17

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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.