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Finding the Fourth Proportional to 120.75, 180.95 and 82.10

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Solution

The fourth proportional to 120.75, 180.95 and 82.10 is: 123.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.75 : 180.95 = 82.10 : x
  2. Step 2: Convert to fraction form
    120.75/180.95 = 82.10/x
  3. Step 3: Cross multiply
    120.75x = 180.95 × 82.10
  4. Step 4: Simplify right side
    120.75x = 14,854.68
  5. Step 5: Solve for x
    x = 14,854.68/120.75
  6. Step 6: Final answer
    x = 123.02

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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.