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Finding the Fourth Proportional to 131.80, 197.34 and 86.20

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Solution

The fourth proportional to 131.80, 197.34 and 86.20 is: 129.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.80 : 197.34 = 86.20 : x
  2. Step 2: Convert to fraction form
    131.80/197.34 = 86.20/x
  3. Step 3: Cross multiply
    131.80x = 197.34 × 86.20
  4. Step 4: Simplify right side
    131.80x = 17,010.71
  5. Step 5: Solve for x
    x = 17,010.71/131.80
  6. Step 6: Final answer
    x = 129.06

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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.