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Finding the Fourth Proportional to 721.45, 995.60 and 406.72

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Solution

The fourth proportional to 721.45, 995.60 and 406.72 is: 561.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.45 : 995.60 = 406.72 : x
  2. Step 2: Convert to fraction form
    721.45/995.60 = 406.72/x
  3. Step 3: Cross multiply
    721.45x = 995.60 × 406.72
  4. Step 4: Simplify right side
    721.45x = 404,925.45
  5. Step 5: Solve for x
    x = 404,925.45/721.45
  6. Step 6: Final answer
    x = 561.27

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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.