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Finding the Fourth Proportional to 102.60, 153.72 and 86.64

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Solution

The fourth proportional to 102.60, 153.72 and 86.64 is: 129.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.60 : 153.72 = 86.64 : x
  2. Step 2: Convert to fraction form
    102.60/153.72 = 86.64/x
  3. Step 3: Cross multiply
    102.60x = 153.72 × 86.64
  4. Step 4: Simplify right side
    102.60x = 13,318.30
  5. Step 5: Solve for x
    x = 13,318.30/102.60
  6. Step 6: Final answer
    x = 129.81

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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.