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Finding the Fourth Proportional to 120.47, 180.52 and 86.30

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Solution

The fourth proportional to 120.47, 180.52 and 86.30 is: 129.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.47 : 180.52 = 86.30 : x
  2. Step 2: Convert to fraction form
    120.47/180.52 = 86.30/x
  3. Step 3: Cross multiply
    120.47x = 180.52 × 86.30
  4. Step 4: Simplify right side
    120.47x = 15,578.43
  5. Step 5: Solve for x
    x = 15,578.43/120.47
  6. Step 6: Final answer
    x = 129.32

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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.