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Finding the Fourth Proportional to 485.20, 726.36 and 438.76

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Solution

The fourth proportional to 485.20, 726.36 and 438.76 is: 656.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.20 : 726.36 = 438.76 : x
  2. Step 2: Convert to fraction form
    485.20/726.36 = 438.76/x
  3. Step 3: Cross multiply
    485.20x = 726.36 × 438.76
  4. Step 4: Simplify right side
    485.20x = 318,697.71
  5. Step 5: Solve for x
    x = 318,697.71/485.20
  6. Step 6: Final answer
    x = 656.84

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.