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Finding the Fourth Proportional to 721.64, 995.78 and 406.85

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Solution

The fourth proportional to 721.64, 995.78 and 406.85 is: 561.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.64 : 995.78 = 406.85 : x
  2. Step 2: Convert to fraction form
    721.64/995.78 = 406.85/x
  3. Step 3: Cross multiply
    721.64x = 995.78 × 406.85
  4. Step 4: Simplify right side
    721.64x = 405,129.13
  5. Step 5: Solve for x
    x = 405,129.13/721.64
  6. Step 6: Final answer
    x = 561.40

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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.