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Finding the Fourth Proportional to 626.31, 863.91 and 390.15

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Solution

The fourth proportional to 626.31, 863.91 and 390.15 is: 538.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.31 : 863.91 = 390.15 : x
  2. Step 2: Convert to fraction form
    626.31/863.91 = 390.15/x
  3. Step 3: Cross multiply
    626.31x = 863.91 × 390.15
  4. Step 4: Simplify right side
    626.31x = 337,054.49
  5. Step 5: Solve for x
    x = 337,054.49/626.31
  6. Step 6: Final answer
    x = 538.16

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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.