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Finding the Fourth Proportional to 66.39, 99.49 and 51.90

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Solution

The fourth proportional to 66.39, 99.49 and 51.90 is: 77.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.39 : 99.49 = 51.90 : x
  2. Step 2: Convert to fraction form
    66.39/99.49 = 51.90/x
  3. Step 3: Cross multiply
    66.39x = 99.49 × 51.90
  4. Step 4: Simplify right side
    66.39x = 5,163.53
  5. Step 5: Solve for x
    x = 5,163.53/66.39
  6. Step 6: Final answer
    x = 77.78

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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.