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Finding the Fourth Proportional to 280.72, 422.16 and 256.96

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Solution

The fourth proportional to 280.72, 422.16 and 256.96 is: 386.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.72 : 422.16 = 256.96 : x
  2. Step 2: Convert to fraction form
    280.72/422.16 = 256.96/x
  3. Step 3: Cross multiply
    280.72x = 422.16 × 256.96
  4. Step 4: Simplify right side
    280.72x = 108,478.23
  5. Step 5: Solve for x
    x = 108,478.23/280.72
  6. Step 6: Final answer
    x = 386.43

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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.