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Finding the Fourth Proportional to 76.81, 106.02 and 47.72

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Solution

The fourth proportional to 76.81, 106.02 and 47.72 is: 65.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.81 : 106.02 = 47.72 : x
  2. Step 2: Convert to fraction form
    76.81/106.02 = 47.72/x
  3. Step 3: Cross multiply
    76.81x = 106.02 × 47.72
  4. Step 4: Simplify right side
    76.81x = 5,059.27
  5. Step 5: Solve for x
    x = 5,059.27/76.81
  6. Step 6: Final answer
    x = 65.87

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.