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Finding the Third Proportional to 428.50 and 661

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Solution

The third proportional to 428.50 and 661 is: 1,019.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.50 : 661 = 661 : x
  2. Step 2: Convert to fraction form
    428.50/661 = 661/x
  3. Step 3: Cross multiply
    428.50x = 661 × 661
  4. Step 4: Simplify right side
    428.50x = 436,921
  5. Step 5: Solve for x
    x = 436,921/428.50
  6. Step 6: Final answer
    x = 1,019.65

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Why These Related Problems?

These problems maintain the same ratio (1.54) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.