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Finding the Fourth Proportional to 320.76, 480.87 and 128.25

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Solution

The fourth proportional to 320.76, 480.87 and 128.25 is: 192.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.76 : 480.87 = 128.25 : x
  2. Step 2: Convert to fraction form
    320.76/480.87 = 128.25/x
  3. Step 3: Cross multiply
    320.76x = 480.87 × 128.25
  4. Step 4: Simplify right side
    320.76x = 61,671.58
  5. Step 5: Solve for x
    x = 61,671.58/320.76
  6. Step 6: Final answer
    x = 192.27

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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.