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Finding the Fourth Proportional to 51.45, 77.21 and 21.04

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Solution

The fourth proportional to 51.45, 77.21 and 21.04 is: 31.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.45 : 77.21 = 21.04 : x
  2. Step 2: Convert to fraction form
    51.45/77.21 = 21.04/x
  3. Step 3: Cross multiply
    51.45x = 77.21 × 21.04
  4. Step 4: Simplify right side
    51.45x = 1,624.20
  5. Step 5: Solve for x
    x = 1,624.20/51.45
  6. Step 6: Final answer
    x = 31.57

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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.