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Finding the Fourth Proportional to 66.91, 100.72 and 51.79

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Solution

The fourth proportional to 66.91, 100.72 and 51.79 is: 77.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.91 : 100.72 = 51.79 : x
  2. Step 2: Convert to fraction form
    66.91/100.72 = 51.79/x
  3. Step 3: Cross multiply
    66.91x = 100.72 × 51.79
  4. Step 4: Simplify right side
    66.91x = 5,216.29
  5. Step 5: Solve for x
    x = 5,216.29/66.91
  6. Step 6: Final answer
    x = 77.96

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.