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Finding the Fourth Proportional to 51.78, 77.70 and 21.37

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Solution

The fourth proportional to 51.78, 77.70 and 21.37 is: 32.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.78 : 77.70 = 21.37 : x
  2. Step 2: Convert to fraction form
    51.78/77.70 = 21.37/x
  3. Step 3: Cross multiply
    51.78x = 77.70 × 21.37
  4. Step 4: Simplify right side
    51.78x = 1,660.36
  5. Step 5: Solve for x
    x = 1,660.36/51.78
  6. Step 6: Final answer
    x = 32.06

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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.