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Finding the Fourth Proportional to 771.72, 1,158.28 and 406.78

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Solution

The fourth proportional to 771.72, 1,158.28 and 406.78 is: 610.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.72 : 1,158.28 = 406.78 : x
  2. Step 2: Convert to fraction form
    771.72/1,158.28 = 406.78/x
  3. Step 3: Cross multiply
    771.72x = 1,158.28 × 406.78
  4. Step 4: Simplify right side
    771.72x = 471,165.14
  5. Step 5: Solve for x
    x = 471,165.14/771.72
  6. Step 6: Final answer
    x = 610.54

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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.