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Finding the Fourth Proportional to 612.38, 845.35 and 391.28

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Solution

The fourth proportional to 612.38, 845.35 and 391.28 is: 540.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.38 : 845.35 = 391.28 : x
  2. Step 2: Convert to fraction form
    612.38/845.35 = 391.28/x
  3. Step 3: Cross multiply
    612.38x = 845.35 × 391.28
  4. Step 4: Simplify right side
    612.38x = 330,769.68
  5. Step 5: Solve for x
    x = 330,769.68/612.38
  6. Step 6: Final answer
    x = 540.14

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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.