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Finding the Fourth Proportional to 276.75, 381.78 and 221.56

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Solution

The fourth proportional to 276.75, 381.78 and 221.56 is: 305.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    276.75 : 381.78 = 221.56 : x
  2. Step 2: Convert to fraction form
    276.75/381.78 = 221.56/x
  3. Step 3: Cross multiply
    276.75x = 381.78 × 221.56
  4. Step 4: Simplify right side
    276.75x = 84,587.18
  5. Step 5: Solve for x
    x = 84,587.18/276.75
  6. Step 6: Final answer
    x = 305.64

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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.