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Finding the Fourth Proportional to 123.90, 171.13 and 82.38

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Solution

The fourth proportional to 123.90, 171.13 and 82.38 is: 113.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.90 : 171.13 = 82.38 : x
  2. Step 2: Convert to fraction form
    123.90/171.13 = 82.38/x
  3. Step 3: Cross multiply
    123.90x = 171.13 × 82.38
  4. Step 4: Simplify right side
    123.90x = 14,098.43
  5. Step 5: Solve for x
    x = 14,098.43/123.90
  6. Step 6: Final answer
    x = 113.79

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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.