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Finding the Fourth Proportional to 621.31, 853.17 and 555.79

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Solution

The fourth proportional to 621.31, 853.17 and 555.79 is: 763.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.31 : 853.17 = 555.79 : x
  2. Step 2: Convert to fraction form
    621.31/853.17 = 555.79/x
  3. Step 3: Cross multiply
    621.31x = 853.17 × 555.79
  4. Step 4: Simplify right side
    621.31x = 474,183.35
  5. Step 5: Solve for x
    x = 474,183.35/621.31
  6. Step 6: Final answer
    x = 763.20

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.