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Finding the Fourth Proportional to 721.05, 995 and 406.28

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Solution

The fourth proportional to 721.05, 995 and 406.28 is: 560.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.05 : 995 = 406.28 : x
  2. Step 2: Convert to fraction form
    721.05/995 = 406.28/x
  3. Step 3: Cross multiply
    721.05x = 995 × 406.28
  4. Step 4: Simplify right side
    721.05x = 404,248.60
  5. Step 5: Solve for x
    x = 404,248.60/721.05
  6. Step 6: Final answer
    x = 560.64

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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.