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Finding the Fourth Proportional to 131.10, 180.90 and 91.80

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Solution

The fourth proportional to 131.10, 180.90 and 91.80 is: 126.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.10 : 180.90 = 91.80 : x
  2. Step 2: Convert to fraction form
    131.10/180.90 = 91.80/x
  3. Step 3: Cross multiply
    131.10x = 180.90 × 91.80
  4. Step 4: Simplify right side
    131.10x = 16,606.62
  5. Step 5: Solve for x
    x = 16,606.62/131.10
  6. Step 6: Final answer
    x = 126.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.