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Finding the Third Proportional to 7.78 and 21.03

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Solution

The third proportional to 7.78 and 21.03 is: 56.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.78 : 21.03 = 21.03 : x
  2. Step 2: Convert to fraction form
    7.78/21.03 = 21.03/x
  3. Step 3: Cross multiply
    7.78x = 21.03 × 21.03
  4. Step 4: Simplify right side
    7.78x = 442.31
  5. Step 5: Solve for x
    x = 442.31/7.78
  6. Step 6: Final answer
    x = 56.84

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Why These Related Problems?

These problems maintain the same ratio (2.70) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.