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Finding the Fourth Proportional to 255.15, 381.51 and 218.90

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Solution

The fourth proportional to 255.15, 381.51 and 218.90 is: 327.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.15 : 381.51 = 218.90 : x
  2. Step 2: Convert to fraction form
    255.15/381.51 = 218.90/x
  3. Step 3: Cross multiply
    255.15x = 381.51 × 218.90
  4. Step 4: Simplify right side
    255.15x = 83,513.49
  5. Step 5: Solve for x
    x = 83,513.49/255.15
  6. Step 6: Final answer
    x = 327.31

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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.