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Finding the Fourth Proportional to 70.68, 106.09 and 66.86

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Solution

The fourth proportional to 70.68, 106.09 and 66.86 is: 100.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.68 : 106.09 = 66.86 : x
  2. Step 2: Convert to fraction form
    70.68/106.09 = 66.86/x
  3. Step 3: Cross multiply
    70.68x = 106.09 × 66.86
  4. Step 4: Simplify right side
    70.68x = 7,093.18
  5. Step 5: Solve for x
    x = 7,093.18/70.68
  6. Step 6: Final answer
    x = 100.36

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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.