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Finding the Fourth Proportional to 103.25, 142.43 and 85.67

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Solution

The fourth proportional to 103.25, 142.43 and 85.67 is: 118.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.25 : 142.43 = 85.67 : x
  2. Step 2: Convert to fraction form
    103.25/142.43 = 85.67/x
  3. Step 3: Cross multiply
    103.25x = 142.43 × 85.67
  4. Step 4: Simplify right side
    103.25x = 12,200.84
  5. Step 5: Solve for x
    x = 12,200.84/103.25
  6. Step 6: Final answer
    x = 118.17

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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.