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Finding the Fourth Proportional to 142.79, 197.05 and 87.56

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Solution

The fourth proportional to 142.79, 197.05 and 87.56 is: 120.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.79 : 197.05 = 87.56 : x
  2. Step 2: Convert to fraction form
    142.79/197.05 = 87.56/x
  3. Step 3: Cross multiply
    142.79x = 197.05 × 87.56
  4. Step 4: Simplify right side
    142.79x = 17,252.71
  5. Step 5: Solve for x
    x = 17,252.71/142.79
  6. Step 6: Final answer
    x = 120.83

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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.