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Finding the Fourth Proportional to 84.14, 115.86 and 78.38

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Solution

The fourth proportional to 84.14, 115.86 and 78.38 is: 107.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.14 : 115.86 = 78.38 : x
  2. Step 2: Convert to fraction form
    84.14/115.86 = 78.38/x
  3. Step 3: Cross multiply
    84.14x = 115.86 × 78.38
  4. Step 4: Simplify right side
    84.14x = 9,081.11
  5. Step 5: Solve for x
    x = 9,081.11/84.14
  6. Step 6: Final answer
    x = 107.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.