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Finding the Fourth Proportional to 780.20, 1,076.67 and 518.27

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Solution

The fourth proportional to 780.20, 1,076.67 and 518.27 is: 715.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.20 : 1,076.67 = 518.27 : x
  2. Step 2: Convert to fraction form
    780.20/1,076.67 = 518.27/x
  3. Step 3: Cross multiply
    780.20x = 1,076.67 × 518.27
  4. Step 4: Simplify right side
    780.20x = 558,000.38
  5. Step 5: Solve for x
    x = 558,000.38/780.20
  6. Step 6: Final answer
    x = 715.21

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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.