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Finding the Fourth Proportional to 70.14, 105.82 and 66.78

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Solution

The fourth proportional to 70.14, 105.82 and 66.78 is: 100.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.14 : 105.82 = 66.78 : x
  2. Step 2: Convert to fraction form
    70.14/105.82 = 66.78/x
  3. Step 3: Cross multiply
    70.14x = 105.82 × 66.78
  4. Step 4: Simplify right side
    70.14x = 7,066.66
  5. Step 5: Solve for x
    x = 7,066.66/70.14
  6. Step 6: Final answer
    x = 100.75

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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.