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Finding the Fourth Proportional to 131.20, 196.80 and 90.58

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Solution

The fourth proportional to 131.20, 196.80 and 90.58 is: 135.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.20 : 196.80 = 90.58 : x
  2. Step 2: Convert to fraction form
    131.20/196.80 = 90.58/x
  3. Step 3: Cross multiply
    131.20x = 196.80 × 90.58
  4. Step 4: Simplify right side
    131.20x = 17,826.14
  5. Step 5: Solve for x
    x = 17,826.14/131.20
  6. Step 6: Final answer
    x = 135.87

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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.