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Finding the Fourth Proportional to 321.39, 482.21 and 129.15

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Solution

The fourth proportional to 321.39, 482.21 and 129.15 is: 193.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.39 : 482.21 = 129.15 : x
  2. Step 2: Convert to fraction form
    321.39/482.21 = 129.15/x
  3. Step 3: Cross multiply
    321.39x = 482.21 × 129.15
  4. Step 4: Simplify right side
    321.39x = 62,276.78
  5. Step 5: Solve for x
    x = 62,276.78/321.39
  6. Step 6: Final answer
    x = 193.77

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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.