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Finding the Fourth Proportional to 721.44, 995.60 and 389.87

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Solution

The fourth proportional to 721.44, 995.60 and 389.87 is: 538.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.44 : 995.60 = 389.87 : x
  2. Step 2: Convert to fraction form
    721.44/995.60 = 389.87/x
  3. Step 3: Cross multiply
    721.44x = 995.60 × 389.87
  4. Step 4: Simplify right side
    721.44x = 388,153.08
  5. Step 5: Solve for x
    x = 388,153.08/721.44
  6. Step 6: Final answer
    x = 538.02

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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.