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Finding the Fourth Proportional to 625.15, 862.20 and 438.78

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Solution

The fourth proportional to 625.15, 862.20 and 438.78 is: 605.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    625.15 : 862.20 = 438.78 : x
  2. Step 2: Convert to fraction form
    625.15/862.20 = 438.78/x
  3. Step 3: Cross multiply
    625.15x = 862.20 × 438.78
  4. Step 4: Simplify right side
    625.15x = 378,316.12
  5. Step 5: Solve for x
    x = 378,316.12/625.15
  6. Step 6: Final answer
    x = 605.16

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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.