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Finding the Fourth Proportional to 131.20, 197.12 and 77.28

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Solution

The fourth proportional to 131.20, 197.12 and 77.28 is: 116.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.20 : 197.12 = 77.28 : x
  2. Step 2: Convert to fraction form
    131.20/197.12 = 77.28/x
  3. Step 3: Cross multiply
    131.20x = 197.12 × 77.28
  4. Step 4: Simplify right side
    131.20x = 15,233.43
  5. Step 5: Solve for x
    x = 15,233.43/131.20
  6. Step 6: Final answer
    x = 116.11

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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.