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Finding the Fourth Proportional to 102.58, 154.19 and 81.30

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Solution

The fourth proportional to 102.58, 154.19 and 81.30 is: 122.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.58 : 154.19 = 81.30 : x
  2. Step 2: Convert to fraction form
    102.58/154.19 = 81.30/x
  3. Step 3: Cross multiply
    102.58x = 154.19 × 81.30
  4. Step 4: Simplify right side
    102.58x = 12,535.65
  5. Step 5: Solve for x
    x = 12,535.65/102.58
  6. Step 6: Final answer
    x = 122.20

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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.