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Finding the Fourth Proportional to 102.42, 141.23 and 87.71

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Solution

The fourth proportional to 102.42, 141.23 and 87.71 is: 120.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.42 : 141.23 = 87.71 : x
  2. Step 2: Convert to fraction form
    102.42/141.23 = 87.71/x
  3. Step 3: Cross multiply
    102.42x = 141.23 × 87.71
  4. Step 4: Simplify right side
    102.42x = 12,388.09
  5. Step 5: Solve for x
    x = 12,388.09/102.42
  6. Step 6: Final answer
    x = 120.95

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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.