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Finding the Fourth Proportional to 721.70, 995.36 and 485.57

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Solution

The fourth proportional to 721.70, 995.36 and 485.57 is: 669.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.70 : 995.36 = 485.57 : x
  2. Step 2: Convert to fraction form
    721.70/995.36 = 485.57/x
  3. Step 3: Cross multiply
    721.70x = 995.36 × 485.57
  4. Step 4: Simplify right side
    721.70x = 483,313.19
  5. Step 5: Solve for x
    x = 483,313.19/721.70
  6. Step 6: Final answer
    x = 669.69

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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.