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Finding the Fourth Proportional to 120.39, 180.58 and 55.40

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Solution

The fourth proportional to 120.39, 180.58 and 55.40 is: 83.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.39 : 180.58 = 55.40 : x
  2. Step 2: Convert to fraction form
    120.39/180.58 = 55.40/x
  3. Step 3: Cross multiply
    120.39x = 180.58 × 55.40
  4. Step 4: Simplify right side
    120.39x = 10,003.77
  5. Step 5: Solve for x
    x = 10,003.77/120.39
  6. Step 6: Final answer
    x = 83.09

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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.