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Finding the Fourth Proportional to 120.05, 179.75 and 81.47

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Solution

The fourth proportional to 120.05, 179.75 and 81.47 is: 121.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.05 : 179.75 = 81.47 : x
  2. Step 2: Convert to fraction form
    120.05/179.75 = 81.47/x
  3. Step 3: Cross multiply
    120.05x = 179.75 × 81.47
  4. Step 4: Simplify right side
    120.05x = 14,642.93
  5. Step 5: Solve for x
    x = 14,642.93/120.05
  6. Step 6: Final answer
    x = 121.98

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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.