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Finding the Fourth Proportional to 720.43, 994.20 and 405.68

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Solution

The fourth proportional to 720.43, 994.20 and 405.68 is: 559.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.43 : 994.20 = 405.68 : x
  2. Step 2: Convert to fraction form
    720.43/994.20 = 405.68/x
  3. Step 3: Cross multiply
    720.43x = 994.20 × 405.68
  4. Step 4: Simplify right side
    720.43x = 403,327.06
  5. Step 5: Solve for x
    x = 403,327.06/720.43
  6. Step 6: Final answer
    x = 559.85

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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.