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Finding the Fourth Proportional to 142.81, 197.01 and 87.55

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Solution

The fourth proportional to 142.81, 197.01 and 87.55 is: 120.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.81 : 197.01 = 87.55 : x
  2. Step 2: Convert to fraction form
    142.81/197.01 = 87.55/x
  3. Step 3: Cross multiply
    142.81x = 197.01 × 87.55
  4. Step 4: Simplify right side
    142.81x = 17,248.23
  5. Step 5: Solve for x
    x = 17,248.23/142.81
  6. Step 6: Final answer
    x = 120.78

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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.