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Finding the Fourth Proportional to 74.14, 111.86 and 70.78

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Solution

The fourth proportional to 74.14, 111.86 and 70.78 is: 106.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.14 : 111.86 = 70.78 : x
  2. Step 2: Convert to fraction form
    74.14/111.86 = 70.78/x
  3. Step 3: Cross multiply
    74.14x = 111.86 × 70.78
  4. Step 4: Simplify right side
    74.14x = 7,917.45
  5. Step 5: Solve for x
    x = 7,917.45/74.14
  6. Step 6: Final answer
    x = 106.79

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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.