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Finding the Fourth Proportional to 721.50, 995.72 and 406.81

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Solution

The fourth proportional to 721.50, 995.72 and 406.81 is: 561.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.50 : 995.72 = 406.81 : x
  2. Step 2: Convert to fraction form
    721.50/995.72 = 406.81/x
  3. Step 3: Cross multiply
    721.50x = 995.72 × 406.81
  4. Step 4: Simplify right side
    721.50x = 405,068.85
  5. Step 5: Solve for x
    x = 405,068.85/721.50
  6. Step 6: Final answer
    x = 561.43

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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.