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Finding the Fourth Proportional to 676.97, 1,015.50 and 387.80

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Solution

The fourth proportional to 676.97, 1,015.50 and 387.80 is: 581.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    676.97 : 1,015.50 = 387.80 : x
  2. Step 2: Convert to fraction form
    676.97/1,015.50 = 387.80/x
  3. Step 3: Cross multiply
    676.97x = 1,015.50 × 387.80
  4. Step 4: Simplify right side
    676.97x = 393,805.82
  5. Step 5: Solve for x
    x = 393,805.82/676.97
  6. Step 6: Final answer
    x = 581.72

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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.