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Finding the Fourth Proportional to 70.70, 106.59 and 66.78

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Solution

The fourth proportional to 70.70, 106.59 and 66.78 is: 100.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.70 : 106.59 = 66.78 : x
  2. Step 2: Convert to fraction form
    70.70/106.59 = 66.78/x
  3. Step 3: Cross multiply
    70.70x = 106.59 × 66.78
  4. Step 4: Simplify right side
    70.70x = 7,118.08
  5. Step 5: Solve for x
    x = 7,118.08/70.70
  6. Step 6: Final answer
    x = 100.68

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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.