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Finding the Fourth Proportional to 721.20, 995.82 and 485.35

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Solution

The fourth proportional to 721.20, 995.82 and 485.35 is: 670.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.20 : 995.82 = 485.35 : x
  2. Step 2: Convert to fraction form
    721.20/995.82 = 485.35/x
  3. Step 3: Cross multiply
    721.20x = 995.82 × 485.35
  4. Step 4: Simplify right side
    721.20x = 483,321.24
  5. Step 5: Solve for x
    x = 483,321.24/721.20
  6. Step 6: Final answer
    x = 670.16

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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.