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Finding the Fourth Proportional to 51.45, 77.20 and 21.02

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Solution

The fourth proportional to 51.45, 77.20 and 21.02 is: 31.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.45 : 77.20 = 21.02 : x
  2. Step 2: Convert to fraction form
    51.45/77.20 = 21.02/x
  3. Step 3: Cross multiply
    51.45x = 77.20 × 21.02
  4. Step 4: Simplify right side
    51.45x = 1,622.74
  5. Step 5: Solve for x
    x = 1,622.74/51.45
  6. Step 6: Final answer
    x = 31.54

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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.