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Finding the Fourth Proportional to 612.78, 845.32 and 391.50

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Solution

The fourth proportional to 612.78, 845.32 and 391.50 is: 540.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.78 : 845.32 = 391.50 : x
  2. Step 2: Convert to fraction form
    612.78/845.32 = 391.50/x
  3. Step 3: Cross multiply
    612.78x = 845.32 × 391.50
  4. Step 4: Simplify right side
    612.78x = 330,936.60
  5. Step 5: Solve for x
    x = 330,936.60/612.78
  6. Step 6: Final answer
    x = 540.06

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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.