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Finding the Fourth Proportional to 84.17, 125.61 and 78.81

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Solution

The fourth proportional to 84.17, 125.61 and 78.81 is: 117.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.17 : 125.61 = 78.81 : x
  2. Step 2: Convert to fraction form
    84.17/125.61 = 78.81/x
  3. Step 3: Cross multiply
    84.17x = 125.61 × 78.81
  4. Step 4: Simplify right side
    84.17x = 9,899.32
  5. Step 5: Solve for x
    x = 9,899.32/84.17
  6. Step 6: Final answer
    x = 117.62

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.