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Finding the Fourth Proportional to 153.21, 229.92 and 81.12

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Solution

The fourth proportional to 153.21, 229.92 and 81.12 is: 121.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.21 : 229.92 = 81.12 : x
  2. Step 2: Convert to fraction form
    153.21/229.92 = 81.12/x
  3. Step 3: Cross multiply
    153.21x = 229.92 × 81.12
  4. Step 4: Simplify right side
    153.21x = 18,651.11
  5. Step 5: Solve for x
    x = 18,651.11/153.21
  6. Step 6: Final answer
    x = 121.74

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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.