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Finding the Fourth Proportional to 123.61, 185.30 and 80.31

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Solution

The fourth proportional to 123.61, 185.30 and 80.31 is: 120.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.61 : 185.30 = 80.31 : x
  2. Step 2: Convert to fraction form
    123.61/185.30 = 80.31/x
  3. Step 3: Cross multiply
    123.61x = 185.30 × 80.31
  4. Step 4: Simplify right side
    123.61x = 14,881.44
  5. Step 5: Solve for x
    x = 14,881.44/123.61
  6. Step 6: Final answer
    x = 120.39

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.