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Finding the Fourth Proportional to 51.33, 77.01 and 20.87

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Solution

The fourth proportional to 51.33, 77.01 and 20.87 is: 31.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.33 : 77.01 = 20.87 : x
  2. Step 2: Convert to fraction form
    51.33/77.01 = 20.87/x
  3. Step 3: Cross multiply
    51.33x = 77.01 × 20.87
  4. Step 4: Simplify right side
    51.33x = 1,607.02
  5. Step 5: Solve for x
    x = 1,607.02/51.33
  6. Step 6: Final answer
    x = 31.31

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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.