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Finding the Third Proportional to 280.75 and 428.38

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Solution

The third proportional to 280.75 and 428.38 is: 653.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.75 : 428.38 = 428.38 : x
  2. Step 2: Convert to fraction form
    280.75/428.38 = 428.38/x
  3. Step 3: Cross multiply
    280.75x = 428.38 × 428.38
  4. Step 4: Simplify right side
    280.75x = 183,505.14
  5. Step 5: Solve for x
    x = 183,505.14/280.75
  6. Step 6: Final answer
    x = 653.62

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Why These Related Problems?

These problems maintain the same ratio (1.53) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.