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Finding the Third Proportional to 428.50 and 644.75

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Solution

The third proportional to 428.50 and 644.75 is: 970.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.50 : 644.75 = 644.75 : x
  2. Step 2: Convert to fraction form
    428.50/644.75 = 644.75/x
  3. Step 3: Cross multiply
    428.50x = 644.75 × 644.75
  4. Step 4: Simplify right side
    428.50x = 415,702.56
  5. Step 5: Solve for x
    x = 415,702.56/428.50
  6. Step 6: Final answer
    x = 970.13

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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.