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Finding the Fourth Proportional to 255.78, 381.93 and 220.68

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Solution

The fourth proportional to 255.78, 381.93 and 220.68 is: 329.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.78 : 381.93 = 220.68 : x
  2. Step 2: Convert to fraction form
    255.78/381.93 = 220.68/x
  3. Step 3: Cross multiply
    255.78x = 381.93 × 220.68
  4. Step 4: Simplify right side
    255.78x = 84,284.31
  5. Step 5: Solve for x
    x = 84,284.31/255.78
  6. Step 6: Final answer
    x = 329.52

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.