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Finding the Fourth Proportional to 68.70, 102.91 and 57.81

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Solution

The fourth proportional to 68.70, 102.91 and 57.81 is: 86.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.70 : 102.91 = 57.81 : x
  2. Step 2: Convert to fraction form
    68.70/102.91 = 57.81/x
  3. Step 3: Cross multiply
    68.70x = 102.91 × 57.81
  4. Step 4: Simplify right side
    68.70x = 5,948.57
  5. Step 5: Solve for x
    x = 5,948.57/68.70
  6. Step 6: Final answer
    x = 86.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.