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Finding the Fourth Proportional to 51.40, 77.07 and 20.94

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Solution

The fourth proportional to 51.40, 77.07 and 20.94 is: 31.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.40 : 77.07 = 20.94 : x
  2. Step 2: Convert to fraction form
    51.40/77.07 = 20.94/x
  3. Step 3: Cross multiply
    51.40x = 77.07 × 20.94
  4. Step 4: Simplify right side
    51.40x = 1,613.85
  5. Step 5: Solve for x
    x = 1,613.85/51.40
  6. Step 6: Final answer
    x = 31.40

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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.