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Finding the Fourth Proportional to 485.99, 725.45 and 427.61

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Solution

The fourth proportional to 485.99, 725.45 and 427.61 is: 638.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.99 : 725.45 = 427.61 : x
  2. Step 2: Convert to fraction form
    485.99/725.45 = 427.61/x
  3. Step 3: Cross multiply
    485.99x = 725.45 × 427.61
  4. Step 4: Simplify right side
    485.99x = 310,203.91
  5. Step 5: Solve for x
    x = 310,203.91/485.99
  6. Step 6: Final answer
    x = 638.30

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.