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Finding the Fourth Proportional to 381.20, 525.76 and 256.80

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Solution

The fourth proportional to 381.20, 525.76 and 256.80 is: 354.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.20 : 525.76 = 256.80 : x
  2. Step 2: Convert to fraction form
    381.20/525.76 = 256.80/x
  3. Step 3: Cross multiply
    381.20x = 525.76 × 256.80
  4. Step 4: Simplify right side
    381.20x = 135,015.17
  5. Step 5: Solve for x
    x = 135,015.17/381.20
  6. Step 6: Final answer
    x = 354.18

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.