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Finding the Fourth Proportional to 305.28, 422.16 and 256.80

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Solution

The fourth proportional to 305.28, 422.16 and 256.80 is: 355.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.28 : 422.16 = 256.80 : x
  2. Step 2: Convert to fraction form
    305.28/422.16 = 256.80/x
  3. Step 3: Cross multiply
    305.28x = 422.16 × 256.80
  4. Step 4: Simplify right side
    305.28x = 108,410.69
  5. Step 5: Solve for x
    x = 108,410.69/305.28
  6. Step 6: Final answer
    x = 355.12

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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.