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Finding the Fourth Proportional to 102.39, 141.20 and 72.87

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Solution

The fourth proportional to 102.39, 141.20 and 72.87 is: 100.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.39 : 141.20 = 72.87 : x
  2. Step 2: Convert to fraction form
    102.39/141.20 = 72.87/x
  3. Step 3: Cross multiply
    102.39x = 141.20 × 72.87
  4. Step 4: Simplify right side
    102.39x = 10,289.24
  5. Step 5: Solve for x
    x = 10,289.24/102.39
  6. Step 6: Final answer
    x = 100.49

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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.