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Finding the Fourth Proportional to 120.71, 180.95 and 84.15

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Solution

The fourth proportional to 120.71, 180.95 and 84.15 is: 126.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.71 : 180.95 = 84.15 : x
  2. Step 2: Convert to fraction form
    120.71/180.95 = 84.15/x
  3. Step 3: Cross multiply
    120.71x = 180.95 × 84.15
  4. Step 4: Simplify right side
    120.71x = 15,226.52
  5. Step 5: Solve for x
    x = 15,226.52/120.71
  6. Step 6: Final answer
    x = 126.14

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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.