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Finding the Fourth Proportional to 721.86, 996.65 and 555.78

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Solution

The fourth proportional to 721.86, 996.65 and 555.78 is: 767.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.86 : 996.65 = 555.78 : x
  2. Step 2: Convert to fraction form
    721.86/996.65 = 555.78/x
  3. Step 3: Cross multiply
    721.86x = 996.65 × 555.78
  4. Step 4: Simplify right side
    721.86x = 553,918.14
  5. Step 5: Solve for x
    x = 553,918.14/721.86
  6. Step 6: Final answer
    x = 767.35

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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.