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Finding the Fourth Proportional to 286.72, 428 and 280.96

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Solution

The fourth proportional to 286.72, 428 and 280.96 is: 419.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.72 : 428 = 280.96 : x
  2. Step 2: Convert to fraction form
    286.72/428 = 280.96/x
  3. Step 3: Cross multiply
    286.72x = 428 × 280.96
  4. Step 4: Simplify right side
    286.72x = 120,250.88
  5. Step 5: Solve for x
    x = 120,250.88/286.72
  6. Step 6: Final answer
    x = 419.40

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.