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Finding the Fourth Proportional to 131.18, 180.79 and 91.71

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Solution

The fourth proportional to 131.18, 180.79 and 91.71 is: 126.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.18 : 180.79 = 91.71 : x
  2. Step 2: Convert to fraction form
    131.18/180.79 = 91.71/x
  3. Step 3: Cross multiply
    131.18x = 180.79 × 91.71
  4. Step 4: Simplify right side
    131.18x = 16,580.25
  5. Step 5: Solve for x
    x = 16,580.25/131.18
  6. Step 6: Final answer
    x = 126.39

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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.