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Finding the Fourth Proportional to 147.39, 221.09 and 86.46

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Solution

The fourth proportional to 147.39, 221.09 and 86.46 is: 129.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.39 : 221.09 = 86.46 : x
  2. Step 2: Convert to fraction form
    147.39/221.09 = 86.46/x
  3. Step 3: Cross multiply
    147.39x = 221.09 × 86.46
  4. Step 4: Simplify right side
    147.39x = 19,115.01
  5. Step 5: Solve for x
    x = 19,115.01/147.39
  6. Step 6: Final answer
    x = 129.69

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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.