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Finding the Third Proportional to 21 and 51.56

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Solution

The third proportional to 21 and 51.56 is: 126.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    21 : 51.56 = 51.56 : x
  2. Step 2: Convert to fraction form
    21/51.56 = 51.56/x
  3. Step 3: Cross multiply
    21x = 51.56 × 51.56
  4. Step 4: Simplify right side
    21x = 2,658.69
  5. Step 5: Solve for x
    x = 2,658.69/21
  6. Step 6: Final answer
    x = 126.60

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Why These Related Problems?

These problems maintain the same ratio (2.46) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.