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Finding the Fourth Proportional to 131.02, 180.87 and 87.40

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Solution

The fourth proportional to 131.02, 180.87 and 87.40 is: 120.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.02 : 180.87 = 87.40 : x
  2. Step 2: Convert to fraction form
    131.02/180.87 = 87.40/x
  3. Step 3: Cross multiply
    131.02x = 180.87 × 87.40
  4. Step 4: Simplify right side
    131.02x = 15,808.04
  5. Step 5: Solve for x
    x = 15,808.04/131.02
  6. Step 6: Final answer
    x = 120.65

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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.