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Finding the Fourth Proportional to 771.20, 1,153.92 and 429.44

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Solution

The fourth proportional to 771.20, 1,153.92 and 429.44 is: 642.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.20 : 1,153.92 = 429.44 : x
  2. Step 2: Convert to fraction form
    771.20/1,153.92 = 429.44/x
  3. Step 3: Cross multiply
    771.20x = 1,153.92 × 429.44
  4. Step 4: Simplify right side
    771.20x = 495,539.40
  5. Step 5: Solve for x
    x = 495,539.40/771.20
  6. Step 6: Final answer
    x = 642.56

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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.