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Finding the Fourth Proportional to 621.60, 931.37 and 438.61

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Solution

The fourth proportional to 621.60, 931.37 and 438.61 is: 657.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.60 : 931.37 = 438.61 : x
  2. Step 2: Convert to fraction form
    621.60/931.37 = 438.61/x
  3. Step 3: Cross multiply
    621.60x = 931.37 × 438.61
  4. Step 4: Simplify right side
    621.60x = 408,508.20
  5. Step 5: Solve for x
    x = 408,508.20/621.60
  6. Step 6: Final answer
    x = 657.19

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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.