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Finding the Fourth Proportional to 320.87, 481.30 and 128.49

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Solution

The fourth proportional to 320.87, 481.30 and 128.49 is: 192.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.87 : 481.30 = 128.49 : x
  2. Step 2: Convert to fraction form
    320.87/481.30 = 128.49/x
  3. Step 3: Cross multiply
    320.87x = 481.30 × 128.49
  4. Step 4: Simplify right side
    320.87x = 61,841.92
  5. Step 5: Solve for x
    x = 61,841.92/320.87
  6. Step 6: Final answer
    x = 192.74

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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.