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Finding the Fourth Proportional to 142.94, 197.21 and 87.69

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Solution

The fourth proportional to 142.94, 197.21 and 87.69 is: 120.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.94 : 197.21 = 87.69 : x
  2. Step 2: Convert to fraction form
    142.94/197.21 = 87.69/x
  3. Step 3: Cross multiply
    142.94x = 197.21 × 87.69
  4. Step 4: Simplify right side
    142.94x = 17,292.91
  5. Step 5: Solve for x
    x = 17,292.91/142.94
  6. Step 6: Final answer
    x = 120.98

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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.