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Finding the Fourth Proportional to 70.66, 105.86 and 51.31

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Solution

The fourth proportional to 70.66, 105.86 and 51.31 is: 76.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.66 : 105.86 = 51.31 : x
  2. Step 2: Convert to fraction form
    70.66/105.86 = 51.31/x
  3. Step 3: Cross multiply
    70.66x = 105.86 × 51.31
  4. Step 4: Simplify right side
    70.66x = 5,431.54
  5. Step 5: Solve for x
    x = 5,431.54/70.66
  6. Step 6: Final answer
    x = 76.87

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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.