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Finding the Fourth Proportional to 103.31, 142.51 and 61.85

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Solution

The fourth proportional to 103.31, 142.51 and 61.85 is: 85.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.31 : 142.51 = 61.85 : x
  2. Step 2: Convert to fraction form
    103.31/142.51 = 61.85/x
  3. Step 3: Cross multiply
    103.31x = 142.51 × 61.85
  4. Step 4: Simplify right side
    103.31x = 8,813.38
  5. Step 5: Solve for x
    x = 8,813.38/103.31
  6. Step 6: Final answer
    x = 85.31

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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.