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Finding the Fourth Proportional to 51.42, 77.14 and 20.98

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Solution

The fourth proportional to 51.42, 77.14 and 20.98 is: 31.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.42 : 77.14 = 20.98 : x
  2. Step 2: Convert to fraction form
    51.42/77.14 = 20.98/x
  3. Step 3: Cross multiply
    51.42x = 77.14 × 20.98
  4. Step 4: Simplify right side
    51.42x = 1,618.71
  5. Step 5: Solve for x
    x = 1,618.71/51.42
  6. Step 6: Final answer
    x = 31.48

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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.