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Finding the Fourth Proportional to 431.52, 647.28 and 123.39

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Solution

The fourth proportional to 431.52, 647.28 and 123.39 is: 185.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.52 : 647.28 = 123.39 : x
  2. Step 2: Convert to fraction form
    431.52/647.28 = 123.39/x
  3. Step 3: Cross multiply
    431.52x = 647.28 × 123.39
  4. Step 4: Simplify right side
    431.52x = 79,867.88
  5. Step 5: Solve for x
    x = 79,867.88/431.52
  6. Step 6: Final answer
    x = 185.09

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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.