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Finding the Fourth Proportional to 516.80, 721.90 and 516.80

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Solution

The fourth proportional to 516.80, 721.90 and 516.80 is: 721.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    516.80 : 721.90 = 516.80 : x
  2. Step 2: Convert to fraction form
    516.80/721.90 = 516.80/x
  3. Step 3: Cross multiply
    516.80x = 721.90 × 516.80
  4. Step 4: Simplify right side
    516.80x = 373,077.92
  5. Step 5: Solve for x
    x = 373,077.92/516.80
  6. Step 6: Final answer
    x = 721.90

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.