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Finding the Fourth Proportional to 123.39, 170.20 and 86.59

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Solution

The fourth proportional to 123.39, 170.20 and 86.59 is: 119.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.39 : 170.20 = 86.59 : x
  2. Step 2: Convert to fraction form
    123.39/170.20 = 86.59/x
  3. Step 3: Cross multiply
    123.39x = 170.20 × 86.59
  4. Step 4: Simplify right side
    123.39x = 14,736.98
  5. Step 5: Solve for x
    x = 14,736.98/123.39
  6. Step 6: Final answer
    x = 119.43

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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.