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Finding the Fourth Proportional to 120.44, 180.32 and 86.15

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Solution

The fourth proportional to 120.44, 180.32 and 86.15 is: 128.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.44 : 180.32 = 86.15 : x
  2. Step 2: Convert to fraction form
    120.44/180.32 = 86.15/x
  3. Step 3: Cross multiply
    120.44x = 180.32 × 86.15
  4. Step 4: Simplify right side
    120.44x = 15,533.24
  5. Step 5: Solve for x
    x = 15,533.24/120.44
  6. Step 6: Final answer
    x = 128.98

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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.